The 24th International Spin
Symposium
Monday 18 October 2021 - Friday 22 October 2021
Matsue, Shimane Prefecture, Japan

Book of Abstracts

Contents
Exclusive Double Drell-Yan factorization and GTMDs . . . . . . . . . . . . . . . . . . . .

1

About toroidal model of leptons in space-time film theory . . . . . . . . . . . . . . . . .

1

LEAP: Polarized Electron Beams from LPA and their Polarimetry . . . . . . . . . . . . .

1

The Central Role of Beam Polarization at Future e+e- Linear Colliders . . . . . . . . . . .

2The use of beam polarization in the search for dark matter at the ILC . . . . . . . . . . .

2Interplay of beam polarisation and systematic uncertainties in electroweak precision measurements at future e+e- colliders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Spin Density Matrix Elements in Exclusive Muoproduction of ρ0 and ω Mesons at COMPASS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Measurement of Drell-Yan Cross-Section in COMPASS . . . . . . . . . . . . . . . . . . .

3

Deeply Virtual Compton Scattering at COMPASS . . . . . . . . . . . . . . . . . . . . . .

4Exclusive pi0 muoproduction at COMPASS . . . . . . . . . . . . . . . . . . . . . . . . . .

4

Measurements of the exclusive neutral pion electroproduction at Jefferson Lab Hall A experiment E12-06-114 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The deconvolution problem of deeply virtual Compton scattering . . . . . . . . . . . . .

5Accessing pion GPDs through the Sullivan process: is it feasible? . . . . . . . . . . . . .

5

Measurement of target spin (in)dependent asymmetries in dimuon production in pionnucleon collisions at COMPASS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Phenomenological assessment of proton mechanical properties from deeply virtual Compton scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Artificial neural network techniques in modelling of GPDs . . . . . . . . . . . . . . . . .

7Transverse momentum distributions in SIDIS at COMPASS . . . . . . . . . . . . . . . . .

7

Azimuthal single- and double-spin asymmetries in semi-inclusive deep-inelastic lepton
scattering by transversely polarized protons . . . . . . . . . . . . . . . . . . . . . . .

8Overview of HERMES results on longitudinal spin asymmetries . . . . . . . . . . . . . .

8Transverse spin asymmetries in inclusive ρ0 muoproduction at COMPASS . . . . . . . .

9iii

Beam-spin induced polarization of Λ and anti-Λ hyperons in semi-inclusive deep-inelastic
scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9Azimuthal asymmetries in unpolarised semi-inclusive DIS at COMPASS . . . . . . . . .

9Simulation of the polarized quark fragmentation within the string+3P0 model . . . . . . 10
A Polarized Electron Beam Upgrade to SuperKEKB Enabling Precision Electroweak Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Measurement of Beam Polarization with Tau Polarimetry for a Potential SuperKEKB Upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Can the EIC 3 He beam polarization be precisely measured by HJET? . . . . . . . . . . . 11
THE STRING+3P0 MODEL OF HADRONIZATION . . . . . . . . . . . . . . . . . . . . . 12
TMD cross-section factorization for dijet production at the EIC . . . . . . . . . . . . . . 12
Result of the neutron EDM starch at PSI . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Plasma Lens: Prospects and designs of increased yield capture section of polarised e+sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Single-spin asymmetry in the reaction p^ + A(p) -> pi0 X . . . . . . . . . . . . . . . . . . 14
Orbit Response Matrix Analysis for COSY - Model Optimization using LOCO . . . . . . 14
Spin asymmetries in electron-jet production at the EIC . . . . . . . . . . . . . . . . . . . 15
Test of discrete symmetries with spin observables at J-PET . . . . . . . . . . . . . . . . . 15
Novel mechanisms for the generation of EDMs in paramagnetic atoms and molecules via
hadronic sources of CP violation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
muEDM: Towards a search for the muon electric dipole moment at PSI using the frozenspin technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Polarized target experiments at LHC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Measurement of longitudinal spin transfer of the Λ(Λ̄) hyperon in longitudinally polarized√
p+p collisions at s = 200 GeV at RHIC-STAR . . . . . . . . . . . . . . . . . . . . 18
Exploring the Quark Transversity and the Collins Fragmentation Functions using Polarized
pp Collisions at STAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Pellet target development for storage ring EDM polarimetry . . . . . . . . . . . . . . . . 18
Factorized Approach to QED Radiation in Semi-inclusive Deep Inelastic Scattering . . .

19

Towards leading-twist T-odd TMD gluon distributions . . . . . . . . . . . . . . . . . . . 19
EDM in Small Rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Roles of spin-dependent transitions in nuclei on astrophysical processes in stars . . . . . 20
Electric Dipole Moment Measurements at Storage Rings . . . . . . . . . . . . . . . . . . 21

Coherent neutral-pion and eta-meson photoproduction on the deuteron . . . . . . . . . 22
Helicity quasi-PDFs in a large Nc nucleon . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Illuminating the nucleon spin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22√
Transverse Spin Transfer of Λ and Λ Hyperons in Polarized p+p Collisions at s = 200
GeV at RHIC-STAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Longitudinal and transverse polarizations of Λ hyperons in unpolarized SIDIS and e+ e−annihilations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Spin Physics Detector at NICA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Deuteron analyzing powers Ay, Ayy and Axx in dp- elastic scattering at large transverse
momenta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Development of Iron Thin Films for Polarization Analysis of Ultracold Neutrons . . . . . 25
Longitudinal Spin Transfer to Lambda Hyperons in CLAS12 . . . . . . . . . . . . . . . . 25
The precision nEDM measurement with UltraCold Neutrons at TRIUMF . . . . . . . . . 26
Spin tune responce to vertical orbit correction at COSY . . . . . . . . . . . . . . . . . . . 26
Transverse Spin Dependent Azimuthal Correlations of Charged Pion Pairs in p↑ p Collisions√
at s = 200 GeV at STAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Transverse polarization of hyperons in SIDIS from twist-3 gluon fragmentation functions 27
Twist-3 gluon fragmentation contribution to hyperon polarization and its frame independence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Polarization REsearch for Fusion Experiments and Reactors - The PREFER collaboration:
purposes and present status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Simulations of Beam Dynamics and Beam Lifetime for the Prototype EDM Ring . . . . . 29
Nuclear TMDs and 3D imaging in nuclei . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Optically polarized alkali metal cell for muonic helium measurements . . . . . . . . . . . 30
Beam-based alignment at the Cooler Synchrotron (COSY) . . . . . . . . . . . . . . . . . 30
Spin-related measurements on charmed baryons at Belle . . . . . . . . . . . . . . . . . . 31
Exclusive production of Quarkonia and Heavy Flavors to access gluon Generalized Parton
Distributions at EIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Nucleon EDM from polarized DIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
First Extraction of Polarized Sea Asymmetry from Weak Boson Production in Proton-Proton
Collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
The gT(x) contribution to single spin asymmetry in SIDIS . . . . . . . . . . . . . . . . . . 32
transverse spin sum rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

New application of a Sona transition unit: Observation of direct transitions between quantum states with energy differences of 10 neV and below . . . . . . . . . . . . . . . . . 33
The search for electric dipole moments of charged particles using storage rings . . . . . 34
Back-to-back proton-pi+ correlations with CLAS12 . . . . . . . . . . . . . . . . . . . . . 34
Spin Transparency Method for High Precision Experiments with Polarized Beams . . . . 34
Neutron Spin Structure from e-3He Scattering with Double Spectator Tagging at the ElectronIon Collider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Studies of Neutral Current Neutrino-Nucleon Scattering with the MicroBooNE Detector

35

Polarized Drell-Yan experiment at Fermilab, SpinQuest (E1039) . . . . . . . . . . . . . . . 36
Dilution factor calculation and its contribution to SpinQuest systematic error . . . . . . 36
Dipole polarizability from small-angle proton scattering and implications for symmetryenergy properties and the formation of neutron skins . . . . . . . . . . . . . . . . . . 37
Global Analysis of SSAs and the Impact of the EIC on Tensor Charge Extractions . . . . 37
Collinear twist-3 approach to hyperon polarization in SIDIS . . . . . . . . . . . . . . . . 38
Towards a surrogate computational tool to quantify the systematic uncertainties in EDM
experiments in storage rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Time-reversal Odd Side of a Jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Small-x Helicity Evolution and the Proton Spin Puzzle . . . . . . . . . . . . . . . . . . . 39
Transverse single-spin asymmetries of W±-bosons in p+p collisions at √s = 510 GeV . .

39

Evolution of primordial neutrino helicities in cosmic magnetic fields and gravitational inhomogeneities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Primordial neutrino helicity modification in magnetic and gravitational fields and implications for their detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Gluon TMDs and J/ψ polarization in SIDIS . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Accessing pion’s large-x gluon by fixed-target charmonium production . . . . . . . . . . 41
TMDs for spin-1 hadrons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Measurement of the anti-quark flavor asymmetry in the proton at FNAL-SeaQuest . . .

42Constraining the Polarized Gluon Distribution Function of the Proton with Recent STAR
Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
The physics program at EIC: towards the realization . . . . . . . . . . . . . . . . . . . . . 43
Status of Lamb-shift polarized ion source at 6 MV tandem accelerator in UTTAC and its
application to nuclear physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Useful relations and sum rules for PDFs and multiparton distribution functions of spin-1
hadrons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

High Precision 5 MeV Mott Polarimeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Measurement of transverse single-spin asymmetries for dijet production in polarized p+p
collisions at \sqrt{s} = 200 GeV at STAR . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Progress on fragmentation-function studies . . . . . . . . . . . . . . . . . . . . . . . . . 46
Transverse Single-Spin Asymmetries for π 0 and Electromagnetic Jets at Forward Rapiditiesin p↑ +p Collisions at Center-of-Mass Energies of 200 GeV and 500 GeV at STAR . . . 46
General helicity formalism for two-hadron production in e+ e− collisions and the Λ polarizing fragmentation function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Experimental studies on the high-energy spin physics in collider experiments at RHIC .

47

Progress on Proton Charge Radius Measurements . . . . . . . . . . . . . . . . . . . . . . 48
Azimuthal asymmetry in J/ψ electroproduction as a probe to linearly polarized gluon
distribution at electon-ion collider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Polarized H2 , D2 and HD molecules and their possible use to feed a polarized H2+ , D2+ or
HD+ ion source for stripping injection into storage rings . . . . . . . . . . . . . . . 48
New aspects of storage-cell developments for the polarized internal target at LHCb . . . 49√
Measurement of Direct Photon Cross Section and Double Helicity Asymmetry at s = 510
GeV in p⃗ + p⃗ Collisions at PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Nucleon isovector tensor charge from lattice QCD with physical light quark masses . . . 50
First global extraction of the worm-gear TMD g1T . . . . . . . . . . . . . . . . . . . . . . 50
Role played by the zero modes in the matching for the twist-3 PDFs . . . . . . . . . . . . 51
Lattice results on twist-3 parton distributions . . . . . . . . . . . . . . . . . . . . . . . . 51
Single-spin asymmetry measurements in inclusive production of K⁰s and ω (782) mesons
at U70 (Protvino). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
POLARIZATION TEST FOR QUASI-FREE KNOCKOUT OF NUCLEON FROM NUCLEAR
SHORT-RANGE CORRELATED NN PAIR . . . . . . . . . . . . . . . . . . . . . . . . 52
NMR With Machine Learning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Weinberg operator contribution to the hadronic CP violation . . . . . . . . . . . . . . . . 53
AI in Spin Physics and the future of spin at Fermilab . . . . . . . . . . . . . . . . . . . . 54
SpinQuest Polarized Target: An Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 54
SU(3)-flavor TMD PDFs extraction with global fits & ANN . . . . . . . . . . . . . . . . . 54
Muon g-2/EDM Experiment at J-PARC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
T-violation in neutron scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Development of a polarized proton target for spin-correlation coefficient measurements

56

Measurement of muon g-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
HIGH VOLTAGE DESIGN AND EVALUATION OF WIEN FILTERS FOR THE CEBAF 200
keV INJECTOR UPGRADE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
New Spin Tracking Software Developed For General Particle Tracer . . . . . . . . . . . . 57
Transverse Single Spin Asymmetry of Forward Neutrons at PHENIX . . . . . . . . . . . 57
Sivers azimuthal asymmetry in inelastic J/ψ leptoproduction . . . . . . . . . . . . . . . 58
Polarization facilities at the JINR accelerator complex . . . . . . . . . . . . . . . . . . . . 58
Machine Learning Online Monitoring for the SpinQuest experiment at Fermilab . . . . . 59
Dynamical Behavior of the SpinQuest Target Polarization due to Beam Heating and Radiation Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Search for permanent EDM using Fr atoms . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Probing gluon TMDs via open heavy flavor quark production at the EIC . . . . . . . . . 60
Online Reconstruction on GPUs for J/ψ TSSA Study at SpinQuest . . . . . . . . . . . . . 61
Novel CFFs Extraction in Unpolarized DVCS . . . . . . . . . . . . . . . . . . . . . . . . . 61
Recent Longitudinal Spin Results with Charged Pions and Jets at PHENIX . . . . . . . . 61
Transverse Single Spin Asymmetries of Midrapidity Heavy Flavor Electrons and Charged
Pions in 200 GeV p↑ + p Collisions at PHENIX . . . . . . . . . . . . . . . . . . . . . . 62
Nuclear spin-isospin responses studied by nuclear reactions: A tribute to Munetake Ichimura. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Geometric model for Drell-Yan processes and TMDs . . . . . . . . . . . . . . . . . . . . . 63
Time-like gravitational formfactors and shear viscosity . . . . . . . . . . . . . . . . . . . 63
Proton-3He elastic scattering at intermediate energies . . . . . . . . . . . . . . . . . . . . 63
Axial Vortical Effect and polarization of resonances in heavy-ion collisions . . . . . . . . 64
The role of the chiral anomaly in polarized deeply inelastic scattering: Topological screening and emergent axion-like dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Measurement of Polarization Transfer in Møller Scattering . . . . . . . . . . . . . . . . . 65
Explore double slit interference effect with linearly polarized photons in UPCs . . . . . . 65
Spin effects in low-energy electron-nucleon scattering with two-photon exchange: Analysis based on 1/N_c expansion of QCD . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
A High-Magnetic-Field Polarized 3He Target for JLab’s CLAS12 . . . . . . . . . . . . . . 66
A new search for time-reversal symmetry-breaking in muon decays . . . . . . . . . . . . 66
Extracting the Λ polarizing Fragmentation Function from Belle e+ e− data within the TMD
formalism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Beam spin asymmetries of π + π 0 and π − π 0 dihadrons from SIDIS at CLAS12 . . . . . . . 67
A versatile bulk superconducting MgB2 cylinder for the production of holding magnetic
field for polarized fuels and targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Three-loop corrections to the quark and gluon decomposition of the QCD trace anomaly
and their applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
The MOLLER experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Weak charge distribution of 208Pb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
CREX: The Calcium weak Radius Experiment . . . . . . . . . . . . . . . . . . . . . . . . 70
TMDs and EIC impact studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Progress in the extraction of unpolarized TMDs from global data sets . . . . . . . . . . . 70
Transverse Single-Spin Asymmetries of Midrapidity Direct Photons and Neutral Mesons at
PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Spin depolarization in high energy electron storage rings: stochastic differential equations,the reduced Bloch equation and the invariant-spin-field approximation . . . . . . . . 71
CP-violating gluon operators and neutron EDM from the QCD instanton vacuum . . . . 72
Spin contents of Na isotopes towards driplines . . . . . . . . . . . . . . . . . . . . . . . . 73
Fragmentation function measurements from Belle . . . . . . . . . . . . . . . . . . . . . . 73
Opening remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Theory of muon g-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Progress on Lattice QCD studies on the spin physics . . . . . . . . . . . . . . . . . . . . 75
ELI-NP project overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Polarization aspects of CMB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Spin Polarization Effects in Heavy Ion Collisions . . . . . . . . . . . . . . . . . . . . . . . 76
Spin-polarized exotic nuclei and beta-NMR: from fundamental interactions, via nuclear
structure, to material science, biology and medicine. . . . . . . . . . . . . . . . . . . 76
An EDM search experiment with ultracold polyatomic molecules . . . . . . . . . . . . . 77
Crystallography of Dynamically Polarized Proteins with Polarized Neutron Beams . . .

77

Theoretical studies on the 3D structure of the nucleon . . . . . . . . . . . . . . . . . . . . 78
Experimental studies on the high-energy spin physics in the fixed-target experiments . . 78
Theoretical studies on the nucleon helicity structure . . . . . . . . . . . . . . . . . . . . . 78
High-energy polarized proton experiments in the USA . . . . . . . . . . . . . . . . . . . 79
High-energy polarized proton accelerators in the USA . . . . . . . . . . . . . . . . . . . 79

Experiments with photon beams at the HIGS facility . . . . . . . . . . . . . . . . . . . . 79
LEPS experiments with polarized photons . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Progress on the new solid polarized target by using the symmetry of Perovskite structure 80
EIC accelerator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
J/psi spin asymmetry measurements in p+p collisions at 200 and 510 GeV by the PHENIX
experiment at RHIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Differential cross sections and photon beam asymmetries of eta photoproduction on the
proton in the LEPS2/BGOegg experiment . . . . . . . . . . . . . . . . . . . . . . . . . 82
Search for the H-dibaryon near ΛΛ and Ξ− p thresholds via 12 C(K − , K + ) reactions at
J-PARC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
The spin-injector for the P2 experiment at MESA . . . . . . . . . . . . . . . . . . . . . . 83
The Hydro-Moeller Polarimeter at MESA . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Report from ISPC meeting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Testing a new polarized target for CLAS12 at Jefferson Lab . . . . . . . . . . . . . . . . . 83
Nuclear Barnett effect and Nuclear Einstein-de Haas effect . . . . . . . . . . . . . . . . . 84
Design and development of the molecular probes for application of the hyperpolarizedNMR/MRI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Materials chemistry of triplet dynamic nuclear polarization . . . . . . . . . . . . . . . . 85
Electron and Nuclear Spin Current Physics and Applications . . . . . . . . . . . . . . . . 85
Status of Polarized Solid Targets in European High Energy Scattering Experiments . . .

86

Concept of projection-type 3D spin-resolving electron detector with spatial resolution andnew type of polarized electron source . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Opening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Optimisation of spin-coherence time in a prototype storage ring for electric dipole momentmeasurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

The 24th International Spin Symposium/ Book of Abstracts

Joint TMD - GPD - HELCITY - Future session EU timezone / 1

Exclusive Double Drell-Yan factorization and GTMDs
Author: Patricia Andrea Gutiérrez García1
1Complutense University of Madrid

In this talk we show how to apply the Soft-Collinear Effective Theory formalism to factorize the
Exclusive Double Drell-Yan process, which gives access to Generalized TMDs as well as double
TMDs. We discuss the relevance of the soft factor in the factorization theorem and its role in thedefinition of the GTMDs.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 2

About toroidal model of leptons in space-time film theory
Author: Alexander Chernitskii1
1

St. Petersburg State Chemical Pharmaceutical University

Corresponding Author: alexander.chernitskii@pharminnotech.com

Nonlinear field model of extremal space-time film is considered [1-3]. Its space-localized solution
in toroidal coordinates with periodic dependence on time is investigated. In particular, we consider
the field configuration having a form of the twisted lightlike soliton moving along the singular ringof the coordinate system. The solutions in the form of twisted lightlike solitons was consideredin the work [1]. As was shown in this work, the subclass of such solitons can be conformed toreal photons. In the present talk, we consider approximate time-periodic toroidal solutions. The
approximate solutions are represented in the form of finite Fourier sums on the circular wave phaseand the polar toroidal coordinate. The dependence of the solution on the radial toroidal coordinate
is approximated by a fractional-rational function from the exponent of the coordinate. The phaseof the circular wave is linearly dependent both on time and the azimuthal toroidal coordinate. The
obtained solutions have the electrical charge and finite energy and angular momentum or spin. The
question as to the relation these solutions to leptons is considered.
[1] A.A. Chernitskii, Lightlike shell solitons of extremal space-time film, Journal of Physics Communications, 2(2018)105013.
[2] A.A. Chernitskii, About long-range interaction of spheroidal solitons in scalar field nonlinear
model, Journal of Physics: Conference Series, 938(2017)012029.
[3] A.A. Chernitskii, Lightlike solitons with spin, Journal of Physics: Conference Series, 678(2016)012016.
[4] A.A. Chernitskii, About toroidal soliton-particle of extremal space-time film, Journal of Physics:
Conference Series, 1435(2020)012054.

Acceleration, Storage and Polarimetry of polarized Beams / 4

LEAP: Polarized Electron Beams from LPA and their Polarimetry
Authors: Jennifer Popp1 ; Felix Stehr2 ; Simon Bohlen2 ; Jenny List2 ; Gudrid Moortgat-Pick3 ; Jens Osterhoff2 ; Kristjan
Poder2
1

Deutsches Elektronen-Synchrotron (DESY)

2

DESY

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University of Hamburg

Corresponding Author: jennifer.popp@desy.de

In recent years, Laser Plasma Acceleration (LPA) has become a promising alternative to conventional
RF accelerators. However, so far, it has only been theoretically shown that polarized LPA beams are
possible.
The LEAP (Laser Electron Acceleration with Polarization) project at DESY aims to demonstrate thisexperimentally for the first time, using a prepolarized plasma target.
The electron polarization will be measured with photon transmission polarimetry. It makes use of
the production of circularly polarized Bremsstrahlung during the passage of the electrons through asuitable target. The photon polarization is then measured with the aid of the transmission asymmetry
related to the magnetization direction of an iron absorber.
In this contribution an overview of the LEAP project and the generation of polarized beams will begiven and simulation studies and a design for the polarimeter will be presented.

Future facilities and experiments / 5

The Central Role of Beam Polarization at Future e+e- Linear Colliders
Author: Ivanka Bozovic Jelisavcic1
1

VINCA Institute of Nuclear Sciences, University of Belgrade (RS)Corresponding Author: gudrid.moortgat-pick@desy.de

In e+e- collisions at energies above the Z resonances, left- andright-handed polarized electrons and positrons are essentiallydifferent species whose cross sections differ by order-1 factors.
This implies that beam polarization can be used as a tool to uncover many aspects of the physics
that these colliders will study. This talk will present a wide variety of examples illustrating thispoint, from the determination of the structure of the Higgs boson couplings, to the search for new schannel resonances, to the enhancement of the collider luminosity for Vector Boson Fusion reactions.
It will also discuss the use of separately adjustable electron and positron polarization to control
backgrounds and understand the magnitude of systematic uncertainties.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 6

The use of beam polarization in the search for dark matter at the
ILC
Author: Ivanka Bozovic Jelisavcic1
1

VINCA Institute of Nuclear Sciences, University of Belgrade (RS)Corresponding Author: filip.zarnecki@fuw.edu.pl

The International Linear Collider has the opportunity to discover dark matter particles in the monophoton signature e+e- -> gamma +(missing). The sensitivity to new physics in this channel depends
crucially on the control and correct estimation of backgrounds. This talk will explain how beampolarization can be used at the ILC to improve the reach of this search.

Future facilities and experiments / 7
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Interplay of beam polarisation and systematic uncertainties inelectroweak precision measurements at future e+e- colliders
Author: Jakob Beyer 1
1

DESY, Germany

Corresponding Author: jenny.list@desy.de

Future high-energy e+e- colliders will provide some of the most precise tests of the Standard Model.
Statistical uncertainties on electroweak precision observables and triple gauge couplings are expected to improve by orders of magnitude over current measurements. This provides a new challengein accurately assessing and minimizing the impact of experimental systematic uncertainties. Beampolarization may hold a unique potential to isolate and determine the size of systematic effects. So
far, studies have mainly focused on the statistical improvements from beam polarisation. This study
aims to assess, for the first time, its impact on systematic uncertainties. A combined fit of precisionobservables, such as chiral fermion couplings and anomalous triple gauge couplings, together withexperimental systematic effects is performed on generator-level differential distribution of 2-fermion
and 4-fermion final-states. Different configurations of available beam polarisations and luminosities
are tested with and without systematic effects, and will be discussed in the context of the existing
projections on fermion and gauge boson couplings from detailed experimental simulations.

Form Factors and GPDs / 9

Spin Density Matrix Elements in Exclusive Muoproduction of ρ0and ω Mesons at COMPASS
Author: Andrzej Sandacz1
1

National Centre for Nuclear Research, Poland

Corresponding Authors: kamil.augsten@cern.ch, andrzej.sandacz@ncbj.gov.pl

We will present results on Spin Density Matrix Elements (SDMEs) measured in hard exclusivsive
muoproduction of ρ0 and ω mesons on the proton at COMPASS using 160 GeV/c polarised µ+ andµ− beams scattering off a liquidhydrogen target. The measurements cover the range 5 GeV/c2 < W < 17 GeV/c2 , 1.0 (GeV/c)2< Q2 < 10.0 (GeV/c)2 and 0.01 (GeV/c)2 < p2T < 0.5 (GeV/c)2 . Here, Q2 denotes the virtuality of
exchanged photon, W the mass of final hadronic system and pT the transverse momentum of thevector meson with respect to the virtual-photon direction. The measured non-zero SDMEs for transitions of transversely polarised virtual photons to longitudinally polarised vector mesons (γT → VL )indicate a considerable violation of s-channel helicity conservation. Additionally, for ρ0 production
we observe a dominant contribution of natural-parity-exchange transitions and a small contributionofunnatural-parity-exchange transitions observed only at small values of W . On the contrary,the contribution of unnatural-parity-exchange for ω production is significant. It decreases with increasing
W , being still non-negligible at the largest W values accessible at COMPASS. The results provide animportant input for modelling Generalised Parton Distribution (GPDs). In particular, they may allow
to evaluate in a model-dependent way the role of parton-helicity flip GPDs (”transversity GPDs”) in
exclusive ρ0 and ω production.

Transverse Momentum Structure (TMD) / 10

Measurement of Drell-Yan Cross-Section in COMPASS
Author: Chia-Yu Hsieh1

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Institute of Physics, Academia Sinica, Taipei, Taiwan

Corresponding Author: cyhsieh@phys.sinica.edu.tw

The COMPASS experiment at CERN performed in 2015 and 2018 Drell-Yan measurements using a
190 GeV negative pion beam scattering off a NH3 target and nuclear aluminium and tungsten targets.
We will present the differential cross section obtained from that measurement in the kinematic in
x-Feynman, transverse momentum, and mass. The results will be valuable input for constraining
parton distribution functions (PDFs) of the pion. We will present preliminary results on Drell-Yan
cross sections and compare them to fixed-order QCD calculations with different pion PDFs. The
kinematic dependence of nuclear effects in Drell-Yan production will be investigated by comparing
the cross sections from three targets of different nuclear mass.

Form Factors and GPDs / 11

Deeply Virtual Compton Scattering at COMPASS
Author: Nicole d’Hose1
1

IRFU CEA-Université Paris-Saclay

Corresponding Authors: jgiarra@cern.ch, nicole.dhose@cea.fr

Deeply Virtual Compton Scattering (DVCS) is the golden exclusive reaction to study Generalized
Parton Distributions (GPDs). Such exclusive measurements were performed at COMPASS in 2016
and 2017 at the M2 beamline of the CERN SPS using the 160 GeV muon beam scattering off a 2.5m
long liquid hydrogen target surrounded by a barrel-shaped time-of-flight system to detect the recoiling target proton. The scattered muons and the produced real photons were detected by the
COMPASS spectrometer, which was supplemented by an additional electromagnetic calorimeter forthe detection of large-angle photons.
The DVCS cross section and its dependence with respect to the squared four-momentum transfer
are extracted from the sum of cross-sections measured with opposite beam charge and polarization.
The goal of the measurement is to determine the transverse extension of the partons in the specific Bjorken x domain of COMPASS between valence quarks and gluons. The analysis method andpreliminary results of the long run will be discussed.

Form Factors and GPDs / 12

Exclusive pi0 muoproduction at COMPASS
Author: Nicole d’Hose1
1

IRFU CEA-Université Paris-Saclay

Corresponding Author: marketa.peskova@cern.ch

Hard Exclusive Meson Production and Deeply Virtual Compton Scattering (DVCS) are very promising reactions to study Generalized Parton Distributions (GPDs). Such exclusive measurements were
performed at COMPASS in 2016 and 2017 at the M2 beamline of the CERN SPS using the 160 GeV
muon beam scattering off a 2.5m long liquid hydrogen target surrounded by a barrel-shaped timeof-flight system to detect the recoiling target proton. The scattered muons and the produced real
photons were detected by the COMPASS spectrometer, which was supplemented by an additional
electromagnetic calorimeter for the detection of large-angle photons.
Exclusive pi0 production is the main source of background for DVCS measurement, while it provides
complementary information for parametrization of GPDs. We will report on preliminary results on
exclusive pi0 production cross section and its dependence on the squared four-momentum transfer
and on the azimuthal angle between the scattering plane and the pi0 production plane. This reaction
is aiming to constrain the GPDs, in particular chiral-odd (“transversity”) GPDs.
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Form Factors and GPDs / 14

Measurements of the exclusive neutral pion electroproduction at
Jefferson Lab Hall A experiment E12-06-114
Author: PO-JU LIN1
1

CEA - Université Paris-Saclay / IJCLab - Orsay

Corresponding Author: plin@colorado.edu

Generalized Parton Distributions (GPDs) provide a 3D picture of the nucleon by correlating the longitudinal momentum to the transverse position of the partons inside of it. In addition to the chiral-even
GPDs, the Deeply Virtual Meson Production (DVMP) also gives access to the chiral-odd (transversity) GPDs and has been providing inputs for the understanding of them. The exclusive productionof π 0 , in the Bjorken limit, is expected to be dominated by the contribution of the longitudinally polarized virtual photon that involves only the chiral-even GPDs, but it turned out not to be the case as
shown by the previous data with limited reach in Q2 . The large contribution from the transversely
polarized photon has been suggested to be the consequence of the convolution of the transversity
GPDs and the Distribution Amplitudes (DA) of the π 0 . The Jefferson Lab Hall A experiment E1206-114 extended the kinematic coverage in the quark valence regime, and has measured the crosssection of exclusive π 0 production off protons at large values of xB (0.36, 0.48, and 0.60) and Q2 (3.1
to 8.4 GeV2 ). In this talk, the results of the E12-06-114 measurement will be presented.

Form Factors and GPDs / 15

The deconvolution problem of deeply virtual Compton scattering
Author: Hervé Dutrieux1
Co-authors: Valerio Bertone 2 ; Cédric Mezrag 2 ; Hervé Moutarde 2 ; Pawel Sznajder 3
1

Irfu, CEA, Université Paris-Saclay

2

Irfu, CEA

3

National Centre for Nuclear Research (NCBJ), Warsaw, Poland

Corresponding Author: herve.dutrieux@cea.fr

Generalised parton distributions are instrumental to study both the three-dimensional structure andthe energy-momentum tensor of the nucleon, and motivate numerous experimental programmes
involving hard exclusive measurements. Based on a next-to-leading order analysis and a careful
study of evolution effects, we exhibit non-trivial generalised parton distributions with arbitrarily
small imprints on deeply virtual Compton scattering observables. This means that in practice thereconstruction of generalised parton distributions from measurements, known as the deconvolution
problem, does not possess a unique solution for this channel. We further discuss the consequenceson the extraction of generalised parton distributions from data and advocate for a multi-channel
analysis.

Joint GPD - Future session / 16

Accessing pion GPDs through the Sullivan process: is it feasible?
Author: Jose Manuel Morgado Chávez1

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Co-authors: Cédric Mezrag 2 ; Feliciano De Soto 3 ; Hervé Moutarde 2 ; Jorge Segovia 3 ; José Rodríguez Quintero 1 ;Maxime Defurne 2
1

Universidad de Huelva

2

DPhN/IRFU/CEA-Saclay

3

Universidad Pablo de Olavide

Corresponding Author: josemanuel.morgado@dci.uhu.es

The description of hadronic structure in terms of quark and gluon degrees of freedom is an open
subject in physics. Great efforts are being devoted to this subject on both the theoretical and experimental sides. Triggered by existing plans to build new experimental facilities such as the EIC (BNL),
and the need to properly interpret the data that are to come, the theoretical interest into the zoologyof parton distribution functions is increasing. Among them, GPDs, which are known to parametrize
the soft-physics taking place in DVCS, are expected to play a central role drawing three-dimensional
images of hadrons. In this work we focus on the study of pions which, as Nambu-Goldstone bosonsof QCD chiral symmetry breaking, provide one of the clearest windows onto the phenomenon of
emergent hadronic mass (EHM). Herein we present a novel class of pion off-forward parton distributions: the so called postitivity-saturated GPDs, which relying on the covariant-extension fulfill
all of the theoretical constraints required by QCD and benefit from a direct interpretation in termsof fundamental degrees of freedom: quarks and gluons. Exploiting them we are capable to obtain
predictions for DVCS on pions to be probed through the Sullivan process at the EIC. We will showthat a measurable asymmetry on the channel arise, therefore pushing optimism about probing pion
structure at future electron-ion colliders.

Transverse Momentum Structure (TMD) / 17

Measurement of target spin (in)dependent asymmetries in dimuon
production in pion-nucleon collisions at COMPASS
Author: Alexandr Chumakov1
1

National Research Tomsk Polytechnic University

Corresponding Author: chumakov@tpu.ru

COMPASS is a fixed-target high energy physics experiment located at the M2 beamline of the Super
Proton Synchrotron at CERN. The study of the spin structure of the nucleon by measuring nucleon
spin (in)dependent azimuthal asymmetries in Drell-Yan process is one of the main topics of thephase-II research programme of the experiment.
In 2015 and 2018 COMPASS performed Drell-Yan measurements using a 190 GeV π − beam interacting with a transversely polarized NH3 and unpolarized nuclear targets. The angular coefficientsthat describe the unpolarized part of the Drell-Yan cross section have been extracted from the datacollected with tungsten target. The results obtained provide important information to study various
perturbative and non-perturbative QCD effects. Performed polarized measurements of the Sivers
and other transverse spin azimuthal asymmetries in Drell-Yan provide a unique possibility to test the(pseudo-)universality of the transverse momentum dependent parton distribution functions.
Measuring the same set of asymmetries in J/ψ production may give an alternative access to parton
distribution functions and serve as input for the study of J/ψ production mechanisms.
In this talk recent preliminary results from the COMPASS Drell-Yan programme will be presented together with related measurements from other experiments and available model predictions.

Joint GPD - Future session / 18
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Phenomenological assessment of proton mechanical properties
from deeply virtual Compton scattering
Author: Hervé MOUTARDE1
Co-authors: Hervé Dutrieux 2 ; Pawel Sznajder 3 ; Cédric Lorcé ; Arkadiusz Trawinski ; Jakub Wagner
1

IRFU, CEA, Université Paris-Saclay

2

Irfu, CEA, Université Paris-Saclay

3

National Centre for Nuclear Research (NCBJ), Warsaw, Poland

Corresponding Author: herve.moutarde@cea.fr

A unique feature of generalised parton distributions is their relation to the QCD energy–momentum
tensor. In particular, they provide access to the mechanical properties of the proton i.e. the distributions of pressure and shear stress induced by its quark and gluon structure. In principle the pressure
distribution can be experimentally determined in a model-independent way from a dispersive analysis of deeply virtual Compton scattering data through the measurement of the subtraction constant.
In practice the kinematic coverage and accuracy of existing experimental data make this endeavour
a challenge. Elaborating on recent global fits of deeply virtual Compton scattering measurements
using artificial neural networks, our analysis presents the current knowledge on this subtraction
constant and assesses the impact of the most frequent systematic assumptions made in this fieldof research. This study will pave the way for future works when more precise data will become
available, e.g. obtained in the foreseen electron-ion colliders EIC and EIcC.

Joint GPD - Future session / 20

Artificial neural network techniques in modelling of GPDs
Authors: Paweł Sznajder1 ; Hervé Moutarde2 ; Oskar Grocholski3
1

National Centre for Nuclear Research

2

Irfu, CEA

3

University of Warsaw

Corresponding Author: pawel.sznajder@ncbj.gov.pl

We discuss the use of machine learning techniques for the modeling of generalized parton distributions in view of their nonparametric estimation from experimental data. Current GPD extractionsindeed suffer from a model dependence which lessens their impact and brings unknown systematics in the estimation of derived quantities like 3D tomography or angular momentum decomposition. On the contrary this new strategy to describe GPDs allows a flexible implementation of theory
driven constraints and provides tools to keep model dependence at a minimum level. We also address aspects of a practical nature like the design and training of artificial neural networks suitable
for this analysis. Getting a better grip on the control of systematic effects, our work will help GPD
phenomenology to achieve its maturity in the precision era of GPD extractions opened by a newgeneration of experiments.

Transverse Momentum Structure (TMD) / 21

Transverse momentum distributions in SIDIS at COMPASS
Author: Anna Martin1
1

Trieste University and INFN

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Corresponding Author: anna.martin@cern.ch

As part of the investigation programme of the transverse spin and transverse momentum structureof the nucleon in semi-inclusive DIS processes, COMPASS has measured several transverse momentum distributions of the final state hadrons in DIS of 160 GeV/c muons off unpolarised targets.
Recently transverse momentum distributions were obtained by scattering the muons off an isoscalartarget consisting of <sup>6</sup>LiD beads immersed in a liquid <sup>3</sup>He/<sup>4</sup>He
mixture.
Here we present the first complete set of results for the transverse momentum distributions ofhadrons produced in DIS off a liquid hydrogen target. These new results allow for a deeper investigation of the various kinematic dependences.
A novel leading-order analysis of the results, aiming to extract the mean value of the squared intrinsic transverse momentum of the quarks, is also presented.

Transverse Momentum Structure (TMD) / 22

Azimuthal single- and double-spin asymmetries in semi-inclusive
deep-inelastic lepton scattering by transversely polarized protons
Authors: Gunar SchnellNone ; For the HERMES CollaborationNone
Corresponding Author: gunar.schnell@desy.de

A comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction of pions, charged kaons, protons, and antiprotons from transversely polarized protons ispresented. These asymmetries include the previously published \hermes results on Collins and Sivers
asymmetries, the analysis of which has been extended to include protons and antiprotons and also to
an extraction in a three-dimensional kinematic binning and enlarged phase space. They are complemented by corresponding results for the remaining four single-spin and four double-spin asymmetries allowed in the one-photon-exchange approximation of the semi-inclusive deep-inelastic scattering process for target-polarization orientation perpendicular to the direction of the incoming lepton
beam. Among those results, significant non-vanishing cos( − ) modulations provide evidence fora sizable worm-gear (II) distribution, 1 . Most of the other modulations are found to be consistent
with zero with the notable exception of large sin modulations for charged pions and +Transverse Momentum Structure (TMD) / 23

Overview of HERMES results on longitudinal spin asymmetries
Authors: Gunar SchnellNone ; For the HERMES CollaborationNone
Corresponding Authors: maruk@yerphi.am, gunar.schnell@desy.de

The HERMES experiment has collected a wealth of data using the 27.6 GeV polarized HERA lepton beam and various polarized and unpolarized gaseous targets. This allows for a series of uniquemeasurements of observables sensitive to the multidimensional (spin) structure of the nucleon, inparticular semi-inclusive deep-inelastic scattering (SIDIS) measurements, for which the HERMES
dual-radiator ring-imaging Cherenkov counter provided final-hadron identification between 2 GeV
to 15 GeV for pions, kaons, and (anti)protons.
In this contribution, longitudinal single- and double-spin asymmetries in SIDIS will be presented.
The azimuthally uniform double-spin asymmetries using longitudinally polarised nucleons constrain
the flavour dependence of the quark-spin contribution to the nucleon spin. For a first time, suchasymmetries are explored differential in three dimensions in Bjorken-x and the in the hadron kinematics z and ℎ⊥ (which respectively represent the energy fraction and transverse momentum of
the final-state hadron) simultaneously. This approach increases the quark-flavour sensitivity and allows to probe the transverse-momentum dependence of the helicity distribution. The measurement
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The 24th International Spin Symposium/ Book of Abstractsof hadron charge-difference asymmetries allows, under certain simplifying assumptions, the direct
extraction of valence-quark polarisations. The azimuthal modulation of this double-spin as well asof the single-(beam)spin asymmetry probe novel quark-gluon-quark correlations through twist-3
distribution and fragmentation functions. Also here asymmetries are explored in several dimensions. Furthermore, in case of the beam-spin asymmetry, results for electro-produced protons andantiprotons have become available. The beam-spin asymmetries for pions are compared to similar
measurements for pions at CLAS and unidentified hadrons at COMPASS.

Transverse Momentum Structure (TMD) / 24

Transverse spin asymmetries in inclusive ρ0 muoproduction at
COMPASS
Author: Bakur Parsamyan1
1

CERN, INFN section of Turin and JINR

Corresponding Author: andrea.moretti@cern.ch

The study of the partonic and spin structure of the nucleon, using semi-inclusive measurementsof hadron muoproduction in Deep Inelastic Scattering (DIS), is one of the main objectives of the
COMPASS experiment at CERN. Within the QCD parton model approach, the nucleon structure in
DIS can be parametrized in terms of Transverse Momentum Dependent (TMD) Parton Distribution
Functions (PDFs), while the hadronization mechanisms are described by the so-called Fragmentation Functions (FFs). Specific convolutions of the TMD PDFs and FFs can be accessed through themeasurement of various spin-dependent azimuthal asymmetries in hadron or dihadron productionsin DIS. The production of vector mesons in SIDIS is potentially interesting to study the polarizedfragmentation and related phenomena. However, this domain is largely unexplored.
In this talk preliminary COMPASS results for the first ever measurement of Collins and Sivers asymmetries in inclusive ρ0 production will be shown. The analysis is based on the SIDIS data-set collected by COMPASS in 2010 using a 160 GeV/c longitudinally polarized µ+ beam impinging on atransversely polarized N H3 target.
The asymmetries were extracted as function of different kinematic variables and confronted withmodel expectations.

Transverse Momentum Structure (TMD) / 25

Beam-spin induced polarization of Λ and anti-Λ hyperons in semiinclusive deep-inelastic scattering
Authors: Gunar SchnellNone ; For the HERMES CollaborationNone
Corresponding Authors: denis_v@mail.desy.de, gunar.schnell@desy.de

The beam-spin induced polarization of Λ and anti-Λ hyperons produced in deep-inelastic scatteringof longitudinally polarized positrons from unpolarized nucleons has been investigated by the HERMES experiment at a positron beam energy of 27.6 GeV. Here, preliminary results are reported fromdata taken in the years
1999 to 2007, including in particular the two high-luminosity periods of 2006 and 2007 enlarging significantly the data set compared to previous HERMES analyses. The two spin-transfer coefficients
D_LX and D_LZ, i.e., transverse and along the hyperon momentum direction, are extracted andstudied as function of the relevant kinematic variables.

Transverse Momentum Structure (TMD) / 26
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Azimuthal asymmetries in unpolarised semi-inclusive DIS at COMPASS
Author: Jan Matousek1
1Charles University (Prague, CZ)

Corresponding Author: jan.matousek@cern.ch

In QCD the momentum and spin structure of the nucleon explored in hard-scattering reactions is
described in terms of Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs).
The PDFs were studied primarily in the collinear approximation, until it was demonstrated that the
intrinsic transverse motion of partons plays an important role.
In Semi-Inclusive Deep Inelastic Scattering (SIDIS) the non-zero transverse momentum of partonskT induces azimuthal dependence of the cross-section and affects the transverse momentum distribution of the produced hadrons. The SIDIS cross-section contains three nucleon polarization independent azimuthal modulations that are related to different combinations of twist-2 or higher twist
PDFs and fragmentation functions. Those are the so-called Cahn effect reflected in cos(ϕh ) modulation, the cos(2ϕh ) term related to the Boer-Mulders PDF and sin(ϕh ) twist-3 effect known as
beam-spin asymmetry.
In 2016 and 2017, the COMPASS experiment at CERN collected a large sample of DIS events using
a longitudinally polarised 160 GeV/c muon beam scattering on a liquid hydrogen target. The azcos(ϕ )cos(2ϕ )sin(ϕ )
imuthal asymmetries AU U h , AU U h and AU U h have been extracted from part of the data. A
new procedure has been developed to subtract a background coming from the decay of diffractively
produced vector mesons. The results presented in this talk qualitatively agree with earlier COMPASS
results obtained with an isoscalar target.

Transverse Momentum Structure (TMD) / 27

Simulation of the polarized quark fragmentation within the string+3P0
model
Author: Albi Kerbizi1
1

INFN Trieste Section

Corresponding Author: albi.kerbizi@ts.infn.it

The recursive quantum mechanical string+3P0 model of polarized quark
fragmentation with pseudoscalar and vector meson production developed recently
has been implemented for the first time in a stand alone Monte Carlo program.
The program allows for a detailed study of the still unknown Collins effect forvector meson production and of the effects of vector meson decays on the
Collins and dihadron asymmetries of the final observed hadrons.
In this talk we present the main results of the Monte Carlo simulations,the comparison with the existing experimental data on SIDIS and e+e- annihilation to hadrons processes,
and predictions for possible new transverse spin asymmetries arising in the vector meson decay processes.
The theoretical aspects of the string+3P0 model are the subject of a different dedicated talk (X.
Artru).

Future facilities and experiments / 28

A Polarized Electron Beam Upgrade to SuperKEKB Enabling Precision Electroweak Measurements
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Author: Michael Roney1
1

University of Victoria

Corresponding Author: mroney@uvic.ca

Consideration is being given to upgrading the SuperKEKB e+ e− collider with polarized electron
beams, which would open a new program of precision electroweak physics at a centre-of-mass energy of 10.58GeV, the mass of the Υ(4S). These measurements include sin2 θW obtained via leftright asymmetry measurements of e+ e− transitions to pairs of electrons, muons, taus, charm andb-quarks. The precision obtainable at SuperKEKB will match that of the LEP/SLC world average
and will thereby probe the neutral current couplings with unprecedented precision at a new energy
scale sensitive to the running of the couplings. At SuperKEKB the measurements of the individual
neutral current vector coupling constants to b-quarks and c-quarks and muons in particular will be
substantially more precise than current world averages and the current 3σ discrepancy between theef f
SLC ALR measurements and LEP AbF B measurements of sin2 θWwill be addressed. This presentation will cover the necessary upgrades to SuperKEKB to achieve and measure the polarization in
the SuperKEKB electron beam.

Acceleration, Storage and Polarimetry of polarized Beams / 29

Measurement of Beam Polarization with Tau Polarimetry for a
Potential SuperKEKB Upgrade
Author: Caleb Miller1
Co-author: Michael Roney 1
1

University of Victoria

Corresponding Author: calebmiller@uvic.ca

A polarized electron beam is being considered as an upgrade for the SuperKEKB accelerator. Having
a polarized beam at Belle II opens a new precision electroweak physics program, as well as improving sensitivity to dark sector and lepton flavour violating processes. In order to achieve a polarized
beam at SuperKEKB a variety of hardware and technical challenges are being studied. The limiting
factor on the precision of these future measurements is expected to be the uncertainty in the beampolarization achieved at the interaction point. The average beam polarization can be measured withhigh precision by making use of the relationship between beam polarization and the kinematics oftau decays.
In order to develop the tau polarimetry measurement technique, in preparation for a polarized electron beam at SuperKEKB, the data collected by BaBar is being analyzed. BaBar has a enough data
to make a polarization measurement with a subpercent statistical uncertainty. This allows the dominant systematic uncertainties to be identified and studied, and the limiting factors for the precisionof tau polarimetry to be established. As Belle II is similar in design to BaBar it is expected a similar or
better level of precision can be achieved with sufficient data and the installation of polarized beams
further motivated.

Acceleration, Storage and Polarimetry of polarized Beams / 30

Can the EIC 3 He beam polarization be precisely measured by HJET?
Author: Andrei Poblaguev1
1

Brookhaven National Laboratory

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Corresponding Author: poblaguev@bnl.gov

The requirements to hadron polarimetry at future Electron Ion Collider (EIC) include measurements
systof the absolute helion (3 He, h) beam polarization with systematic uncertainties better than σP /P ≤1%. Here, we consider a possibility to utilize the Polarized Atomic Hydrogen Gas Jet Target (HJET)
for precision measurement of polarization of the ∼ 100 GeV/n helion beam.
Since 2005, HJET serves to determine absolute proton beam polarization at the Relativistic Heavy
Ion Collider with accuracy δ syst P /P ∼ 0.5%. Concurrent measurement of the beam and target (thejet) spin correlated asymmetries allows one to relate the beam polarization Pbeam = Pjet abeam /ajet
to the well known jet polarization Pjet ∼ 96 ± 0.1%. Thus, the proton beam polarization can bemeasured with actually no knowledge of the proton-proton analyzing power App
N (t).
To adapt the method for the EIC helion beam, it is necessary to know the ratio of p↑ h and h↑ pphhp
analyzing powers Aph
N /AN , which depends on the corresponding hadronic spin-flip amplitudes r5
pp
hp
and r5 . A prospect to derive these amplutudes from the proton-proton one, r5 , measured at HJET
will be discussed.
Potentially, results the 3 He beam polarization measurement can be affected by the helion breakup
in the scattering. However, since only low energy recoil protons are detected at HJET, the breakup
component in the acquired data is expected to be strongly suppressed. To figure out identification of
the breakup events in the 3 He beam measurement at EIC and to evaluate elastic data contamination
by such events, the HJET experimental data obtained with ∼ 10 GeV gold and deuteron beams wasanalyzed.

Transverse Momentum Structure (TMD) / 31

THE STRING+3P0 MODEL OF HADRONIZATION
Author: Xavier Artru1
1

Institut de Physique des deux Infinis de Lyon (IP2I)

Corresponding Author: x.artru@ipnl.in2p3.fr

The Lund String Fragmentation Model, widely used in Monte Carlo generators of jets, is extended toinclude the quark spin as a full quantum-mechanical degree of freedom, described by Pauli spinors.
Such a model is needed to describe consistently the azimuthal asymmetries in jets from polarized
quarks, like the Collins effect, di-hadron asymmetry and jet handedness.
The model is formulated in terms of quark propagators and quark-meson-quark vertices which are
combinations of Pauli matrices. The basic assumption is that, when a string breaks, the created qqbar pair is in the 3P0 state. This is implemented by a quark propagator proportional to mu+sigma_z
sigma.k_T, where mu is a complex mass parameter. The model has been recently translated in a recursive Monte Carlo code for pseudoscalar meson production.
The introduction of vector mesons needed to complete the model requires a special recipe accounting for the entanglement between the spins of the meson and of the left-over quark. The longitudinal
and transverse mesons are coupled to the quark line with two independent complex, constants G_L
and G_T.
The expected properties are chiefly:- Collins asymmetries of the same size but opposite signs for pi+ and pi-,- di-hadron asymmetry linked to the Collins one,- generation of jet handedness,- vector mesons have Collins asymmetries whose signs depend on their linear polarizations,- vector mesons can be generated with oblique (i.e., between transverse and longitudinal) polarizations. This is a new source of di-hadron asymmetry.
The main theoretical aspects of the model are presented in this talk, while the results of MC simulations and their comparison with existing data are the subject of a different dedicated talk (A.
Kerbizi).

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Joint TMD - GPD - HELCITY - Future session EU timezone / 32

TMD cross-section factorization for dijet production at the EIC
Author: Rafael F. del Castillo1
1

Universidad Complutense de Madrid

Corresponding Author: raffer06@ucm.es

We use soft collinear effective theory (SCET) to study a dijet production process in deep-inelasticscattering (DIS), measuring the imbalance of the two hard probes in the Breit frame. In order toachieve factorization of the transverse momentum dependent (TMD) cross-section, we need to introduce a new soft function that we calculate at one-loop, regulating rapidity divergencies with thedelta-regulator. We use consistency relations with heavy meson pair production in DIS to extend theanomalous dimension of the dijet soft function to three loops. We also provide phenomenologicaldiscussion and plots for this process, which is expected to be measured at the future EIC. The studyof these processes could provide new knowledge of the TMD gluon distributions, to which they aresensitive.

Plenary Presentations / 33

Result of the neutron EDM starch at PSI
Author: Georg Bison1
1

Paul Scherrer Institut

Corresponding Author: georg.bison@psi.ch

We report on the result of the neutron EDM experiment which took data in 2015 and 2016 at PSIs
ultracold neutron source. The neutron EDM is deemed to be one of the most sensitive probes ofphysics beyond the standard model. The experiment measured the precession frequency of spinpolarized neutrons as a function of a strong electric field. The electric dipole moment of the neutrons
leads to a linear dependence between those two quantities. After a blinded data analysis by two
independent teams, we concluded that our results do not show this dependence within statisticaluncertainties. We thus published a new upper limit of dn < 1.8 10−26 e cm [1]. The new result alsosignificantly improves systematic uncertainties which will be discussed in detail. We will also givea future outlook on our new apparatus, n2EDM, which is currently set up at PSI.
[1] C. Abel et al. “Measurement of the Permanent Electric Dipole Moment of the Neutron” Phys.
Rev. Lett. 124, 081803 (2020) 10.1103/PhysRevLett.124.081803.

Polarized Sources and Targets / 34

Plasma Lens: Prospects and designs of increased yield capture
section of polarised e+ sources
Authors: Niclas Hamann1 ; Gudrid Moortgat-Pick2 ; Manuel Formela1 ; Klaus Flöttmann3
1

Uni Hamburg

2

University of Hamburg

3

DESY Hamburg

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Corresponding Author: niclas.hamann@desy.de

The ILC is an ambitious international collaboration with its positron source especially being at theforefront of pushing technological boundaries. Part of this enterprise has to be the optical matching device responsible for capturing positrons exiting the target and transforming them from ahighly divergent beam with a small effective cross-section to a wide, parallel beam to be appropriate for the succeeding acceleration sections. This problem has been approached by different typesof sophisticated coils like the quarter wave transformer and flux concentrator for many years now.
Today considerations include the new principle based on an electric current in a plasma. This socalled plasma lens creates a magnetic field, which is in theory especially qualified for optical matching due to its pronounced azimuthal component in contrast to the radial field of conventional devices. The prospect of increased yield would benefit a wide range of sources, particularly polarised
sources.

Spin in Nuclear Reactions and Nuclei / 36

Single-spin asymmetry in the reaction p^ + A(p) -> pi0 X
Author: Victor Abramov1
1

NRC “Kurchatov Institute” - IHEP, Protvino 142281, Moscow region, Russia

Corresponding Author: victor.abramov@ihep.ru

Single-spin asymmetry (AN) in the reaction p^ + A(p) -> pi0 X with transversely polarized proton
beam in pp and pA collisions is analyzed within the framework of the phenomenological model ofchromomagnetic polarization of quarks (CPQ) [1-5]. Numerous existing data are compared withmodel calculations, including recent measurements of pp, pAl and pAu collisions with c.m. energy√s = 200 GeV [6]. There is good agreement between the data and calculations using the CPQ model.
Detailed calculations of AN were performed depending on kinematic variables such as √s, pT, xF andthe atomic weight of the target. In some kinematic regions, unusual behavior is expected, including
asymmetry sign reversal and AN (xF) oscillation. This behavior can be studied in existing and future
experiments.
References[1] Phenomenology of single-spin effects in hadron production at high energies
V.V. Abramov (Serpukhov, IHEP). Dec 2008. 16 pp.
Published in Phys.Atom.Nucl. 72 (2009) 1872-1888, Yad.Fiz. 72 (2009) 1933-1949[2] Single-spin physics: Experimental trends and their origin
V.V. Abramov (Serpukhov, IHEP). 2011. 8 pp.
Published in J.Phys.Conf.Ser. 295 (2011) 012086 Proceedings SPIN2010[3] Polarization phenomena in hadronic reactions
V.V. Abramov (Serpukhov, IHEP). 2014. 4 pp.
Published in Phys.Part.Nucl. 45 (2014) 62-65 DOI: 10.1134/S106377961401002X
Conference: C12-09-17.3 Proceedings SPIN2012[4] On the A-dependence of the neutron single-spin asymmetry in pA-collisions V.V. Abramov Published in: J.Phys.Conf.Ser. 938 (2017) 1, 012038 Proceedings DSPIN-17[5] Possible studies at the first stage of the NICA collider operation with polarized and unpolarized
proton and deuteron beams V.V. Abramov et al. e-Print: 2102.08477 [hep-ph] (Feb 16, 2021)[6] J.Adam et al., STAR Collaboration, Phys.Rev. D 103 (2021) 072005 e-Print: 2012.07146 [nuclex]

Acceleration, Storage and Polarimetry of polarized Beams / 37
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Orbit Response Matrix Analysis for COSY - Model Optimization
using LOCO
Author: Max Vitz1
1

RWTH Aachen, Forschungszentrum Jülich

Corresponding Author: maximilian.vitz@rwth-aachen.de

The matter-antimatter asymmetry might be understood by investigating the EDM (Electric Dipole
Moment) of elementary particles. A permanent EDM of a subatomic particle violates time reversal and parity symmetry at the same time and a discovery of a non-zero EDM would be a strong
indication for physics beyond the Standard Model.
The JEDI-Collaboration (Jülich Electric Dipole moment Investigations) in Jülich has performed a
direct EDM measurement for deuterons with the so called precurser experiments at the storage ring
COSY (COoler SYnchrotron).
In order to understand the measured data and to disentangle an EDM signal from systematic effects,
spin tracking simulations in an accurate simulation model of COSY are needed. Such an accurate
model can be achieved by measuring the ORM (Orbit Response Matrix) of COSY and fitting themodel ORM against the measured ORM using the LOCO (Linear Optics from Closed Orbit) technique.
Therefore, the LOCO algorithm as well as a simulation model of COSY with all knowledge of COSY
available has been implemented into the software library Bmad. First resultsof the lattice optimization and the spin tracking simulations will be discussed.

Transverse Momentum Structure (TMD) / 38

Spin asymmetries in electron-jet production at the EIC
Authors: Zhong-Bo Kang1 ; Kyle Lee2 ; Ding Yu Shao3 ; Fanyi Zhao1
1

University of California, Los Angeles

2

Lawrence Berkeley National Laboratory

3

Fudan University

Corresponding Author: fanyizhao@physics.ucla.edu

The internal structure of jets has been an active research topic in QCD in recent years. In thistalk, we propose to use one particular jet substructure - the so-called jet fragmentation function
to study spin-dependent distribution and dynamics. In particular, we provide the general theoretical framework for studying the distribution of hadrons inside a jet by taking full advantage of thetransverse-momentum-dependent distributions and polarization effects. The key development referred to as “polarized jet fragmentation functions’’, opens up new opportunities to study transverse
momentum dependent (TMD) fragmentation functions via jets. Besides providing the theoreticalunderstanding for the well-known Collins asymmetry for hadron in a jet, we also give additional examples involving polarization of Lambda baryons and pions inside the jet at the future Electron-Ion
Collider.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 39

Test of discrete symmetries with spin observables at J-PET
Author: Eryk Czerwiński1
1

Marian Smoluchowski Institute of Physics, Jagiellonian University

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Corresponding Author: kamil.dulski@doctoral.uj.edu.pl

The Jagiellonian PET (J-PET) detector is the only device which enables estimation of positronium
spin axis together with determination of polarization of photons from positronium annihilation on
the event-by-event basis. This allows to test angular correlations in the annihilations of the lightest leptonic bound system and explore a new class of discrete symmetry odd operators that were
not investigated before. Such measurement is equivalent to a search for possible violation of combined charge, parity, and time-reversal symmetries as yet another approach for a test of New Physic.
Positronium, a bound state of electron and positron, as the lightest matter-antimatter system and at
the same time an eigenstate of the C and P operators is an unique probe in such endeavor. With
first measurements demonstrating such capabilities we are able to reach the precision of CP and
CPT tests at permill level. In the talk we will describe experimental techniques and new results of
discrete symmetries tests in the decays of positronium in a whole available phase-space.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 40

Novel mechanisms for the generation of EDMs in paramagnetic
atoms and molecules via hadronic sources of CP violation
Author: Yevgeny Stadnik1
1Kavli IPMU, University of Tokyo

Corresponding Author: yevgeny.stadnik@ipmu.jp

Rapid advances in searches for the electron EDM have recently been achieved using paramagnetic
molecules, with an improvement in sensitivity by more than 100-fold over the past decade alone[1]. In our recent paper [2], we have identified novel mechanisms for the generation of EDMs inparamagnetic atoms and molecules via hadronic sources of CP violation. If the source of CP violation resides in the hadronic sector, then two-photon-exchange processes between electrons andthe nucleus induce CP-odd semileptonic interactions, providing the dominant source of EDMs inparamagnetic systems instead of via the electron EDM. Unlike the nuclear Schiff moment mechanism in diamagnetic systems, the generation of a nucleon-number-enhanced CP-odd nuclear scalarpolarisability can occur in all possible nuclei and is generally less sensitive to details of the underlying nuclear structure. Using the recent ACME EDM limit from paramagnetic ThO, we have derived
bounds on the QCD theta term, proton EDM, isoscalar CP-odd pion-nucleon coupling, and colour
EDMs of the light quarks.
References[1] Andreev et al. (ACME Collaboration), Nature 562, 355 (2018).
[2] Flambaum, Pospelov, Ritz and Stadnik, Physical Review D 102, 035001 (2020).

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 41

muEDM: Towards a search for the muon electric dipole moment
at PSI using the frozen-spin technique
Author: Mikio Sakurai1
Co-author: On behalf of the muEDM initiative at PSI
1

ETH Zürich

Corresponding Author: msakurai@phys.ethz.ch

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We propose an experiment to search for the permanent electric dipole moment (EDM) of the muonat the Paul Scherrer Institute (PSI), Switzerland, by employing the frozen-spin technique with apotential sensitivity of 6 × 10−23 e·cm [1]. A muon EDM would violate CP symmetry and lepton
flavor universality which makes the search an excellent test for physics beyond the Standard Model(SM). In the light of the recently reported combined 4.2σ deviation from the SM in the muon (g − 2)together with observed tensions in B decays, a dedicated muon EDM experiment is very attractive
not only to further push EDM searches beyond to the first generation of fundamental particles, butalso to probe the role of the lepton flavour universality in nature.
Several R&D studies are underway at PSI in preparation for a high precision experiment to measure
the muon EDM. In 2019, the characterisation of the πE1 and µE1 beamlines at PSI, two potential
beamlines to develop and host the experiment, were performed. The transverse phase space as wellas polarisation of the µ+ beam were measured up to 125 MeV/c to extract essential input parameters
for ongoing Geant4 simulations of the proposed experiment. Multiple scattering of muon decay
positrons would potentially influence strongly the design of the positron tracking scheme. Therefore,
Coulomb multiple scattering of positrons in the momentum range below 85 MeV/c was studied in2020 with a telescope consisting of 3 planes of MALTA CMOS pixel detectors. In this talk, I will
present and discuss the current status and prospects of the muEDM experiment at PSI.
This work is supported by ETH Research Grant ETH-48 18-1.
[1] A. Adelmann et al., Search for a muon EDM using the frozen-spin technique, arXiv:2102.08838[hep-ex] (2021).

Plenary Presentations / 42

Polarized target experiments at LHC
Authors: Luciano Pappalardo1 ; Pasquale Di Nezza2 ; Vittore Carassiti3 ; Giuseppe Ciullo1 ; Paolo Lenisa1 ; Marco
Santimaria4 ; Erhard Steffens5
1

University of Ferrara, Ferrara, Italy

2

INFN Laboratori Nazionali di Frascati, Frascati (Rome), Italy

3

INFN - Sezione di Ferrara, Ferrara, Italy

4

INFN - Laboratori Nazionali di Frascati, Frascati (Rome), Italy

5

Physics Dept., FAU Erlangen-Nürnberg, Erlangen, Germany

Corresponding Author: pappalardo@fe.infn.it

A polarized gaseous target, operated in combination with the high-energy, high-intensity LHC
beams and a highly performing LHC particle detector, has the potential to open new physics frontiersand to deepen our understanding of the intricacies of the strong interaction in the non-perturbative
regime of QCD. Specifically, the LHCspin project aims to develop, in the next few years, innovative
solutions and cutting-edge technologies to access spin physics in high-energy polarized fixed-target
collisions using the LHCb detector. Given its forward geometry (2< <5), the LHCb spectrometer
is, in fact, perfectly suitable to cope with the forward kinematics of these collisions. Furthermore,
being designed and optimized for the detection of heavy hadrons, it will allow to probe the nucleon’s
structure by exploiting new probes, such as inclusive production of c- an b-hadrons, and ideal tool toaccess, e.g., the essentially unexplored spin-dependent gluon TMDs. This configuration, with centerof-mass energies ranging from 115 GeV in pp interactions to 72 GeV per nucleon in collisions withion beams, will allow to explore the nucleon’s internal dynamics at unique kinematic conditions,by covering a wide backward rapidity region, including the poorly explored high x-Bjorken andhigh x-Feynman regimes. This ambitious task poses its basis on the recent installation of SMOG2, astorage-cell based unpolarized gas target in front of the LHCb spectrometer. With the installation of
the proposed polarized target system, LHCb will become the first experiment delivering simultaneously unpolarized beam-beam collisions at 14 TeV and both polarized and unpolarized beam-target
collisions at center-of-mass energies of the order of 100 GeV. The status of the LHCspin project ispresented along with a selection of physics opportunities
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Nucleon Helicity Structure / 43

Measurement of longitudinal spin transfer of √the Λ(Λ̄) hyperon
in longitudinally polarized p+p collisions at s = 200 GeV at
RHIC-STAR
Author: Yi Yu1
1

Shandong University

Since the first surprising results on the spin structure of the proton by the EMC experiment in thelate 1980s, much progress has been made in understanding the origin of the proton spin. However,the sea quark contribution to the proton spin, for example, the helicity distributions of the strange
quark (anti-quark), s(s̄), is still not well constrained by experimental data. Since the s(s̄) is expected
to carry a substantial fraction of the spin of the Λ(Λ̄) hyperon, measurements of the longitudinal
spin transfer, DLL , of the Λ(Λ̄) hyperon can thus shed light on the helicity distribution of the s(s̄)
and the longitudinally polarized fragmentation functions. In this talk, we will present the status ofthe Λ(Λ̄) DLL analysis using data collected at RHIC-STAR in 2015, for the pseudo-rapidity |η| < 1.2
and transverse momenta up to 8.0 GeV/c. The DLL as a function of the longitudinal momentum
fraction of the Λ(Λ̄) hyperon in the jet is also investigated. This data set is about twice as large
as the 2009 data used for the previously published DLL results.In addition, the longitudinal double
spin asymmetries, ALL , of the Λ(Λ̄) hyperon and the KS0 meson are investigated, which are also
expected to be sensitive to the s(s̄) helicity distributions.

Transverse Momentum Structure (TMD) / 44

Exploring the Quark Transversity and the Collins Fragmentation
Functions using Polarized pp Collisions at STAR
Authors: Ting Lin1 ; STAR CollaborationNone
1

Shandong University

Corresponding Author: tinglin@sdu.edu.cn

Understanding the internal spin structure of the nucleon still remains a challenge in strong interaction physics. Transversity, which describes the transverse spin structure of quarks in a transversely
polarized proton, is still poorly constrained by experimental data. Since it is chiral-odd, it can only
be accessed through channels that couple to other chiral-odd distributions, like the Collins fragmentation functions (so-called Collins effect) or the interference fragmentation functions.
Recently, a detailed calculation using the soft-collinear effective theory found that the Collins effectin pp collisions involves a mixture of collinear and transverse momentum dependent (TMD) factorization. The Collins effect provides a direct probe to the Collins fragmentation function and enables
testing of its evolution, universality and factorization breaking in the transverse momentum dependent formalism.
In 2018, STAR published √the first measurements of Collins asymmetries for charged pions in jets inpolarized pp collisions at s = 500 GeV based on data taken during 2011. These measurements probe
Q2 scales one to two orders of magnitude larger than similar measurements in semi-inclusive deepinelastic scattering (SIDIS) and the results are consistent with predictions based on global analysesof e+ e− and SIDIS data.
√
In 2012 and 2015, STAR collected ∼14 pb−1 and ∼48 pb−1 of transversely polarized pp data at s
= 200 GeV, respectively. These datasets provide the most precise measurement of the Collins effectin 200 GeV pp collisions to date, especially at the quark momentum fractions 0.1 ≤ x ≤ 0.4. Preliminary√ results for Collins asymmetries of identified pions, kaons, and protons in jets in pp collisions
at s = 200 GeV and comparisons to theory predictions will be presented.

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Acceleration, Storage and Polarimetry of polarized Beams / 45

Pellet target development for storage ring EDM polarimetry
Author: Otari Javakhishvili1
1

Forschungszentrum Juelich

Corresponding Author: o.javakhishvili@fz-juelich.de

The JEDI (Jülich Electric Dipole moment Investigations) collaboration in Jülich is conducting a set ofexperiments at the COSY accelerator and storage ring, aiming to develop experimental techniques
to measure the EDMs of charged particles, like proton and deuteron. One of the key elements ofthese experiments is the modular polarimeter (JEPO) with a special target system.
In the current configuration, horizontal and vertical block targets are used in the polarimeter. Targets
are mounted on stepper linear actuators and dedicated hardware and software are used to control
target movements during experiments. The EPICS based target control system can access accelerator
and detector data and use them as a feedback for automatic target movement or finding the proper
beam position for measurement. The system is controlled by the network interface using dedicated,user friendly GUI. It has several safety modules which consist of software and hardware interlock
systems.
The work on a special target system, which will oscillate carbon pellets through the beam is ongoing.
The frequency and the speed of oscillation must be variable to achieve the desired effective target
density. This kind of target will require a specialised monitoring and control system, consisting ofseveral electrical and mechanical parts. The system will include precise triggering, object detection,
track reconstruction and data synchronization units. Control signals and data will be exchanged
using a network interface, which will provide the ability to synchronize data of the target with othersystems in the detector.
In this contribution achievements and experimental results will be summarized and ongoing activities towards the dedicated ballistic pellet target development presented.

Transverse Momentum Structure (TMD) / 48

Factorized Approach to QED Radiation in Semi-inclusive Deep
Inelastic Scattering
Authors: Tianbo Liu1 ; W. Melnitchouk2 ; Jianwei Qiu2 ; N. Sato2
1

Shandong University2

Jefferson Lab

Corresponding Author: liutb@sdu.edu.cn

Semi-inclusive deep inelastic scattering (SIDIS) is one of the key processes to extract transverse momentum dependent parton distributions (TMDs). An advantage of electrons is that they are muchcleaner probes of nucleon structure than hadron beams, but, at the same time, electron scattering atlarge momentum transfer can be a source of considerable photon radiation, which can significantly
distort the inferred nucleon structure. In this talk, I will present a new factorized approach to SIDIS,
treating QED and QCD radiation on equal footing and providing a systematically improvable approximation to the extraction of TMDs. I will show how radiation effects prevent a well-defined “photonhadron” frame, forcing one to use a two-step process to account for the radiation, and demonstrate
how the QED contributions can be well approximated by collinear factorization. I will illustrate theutility of the new method by explicit application to transverse single spin asymmetries.

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Transverse Momentum Structure (TMD) / 49

Towards leading-twist T-odd TMD gluon distributions
Authors: Alessandro Bacchetta1 ; Francesco Giovanni Celiberto2 ; Marco Radici3
1

Università di Pavia and INFN2

ECT*/FBK Trento & INFN-TIFPA

3

INFN, Sezione di Pavia

Corresponding Author: francescogiovanni.celiberto@unipv.it

We perform explorative analyses of the 3D gluon content of the proton via a study of polarized
T-odd gluon TMDs at leading twist, calculated in a spectator model for the parent nucleon. Our
approach encodes a flexible parameterization for the spectator-mass density, suited to describe bothmoderate and small-x effects. All these prospective developments are relevant in the investigationof the gluon dynamics inside nucleons and nuclei, which constitutes one of the major goals of newgeneration colliding machines, as the Electron-Ion Collider, the High-Luminosity LHC, NICA-SPD,and the Forward Physics Facility.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 50

EDM in Small Rings
Authors: R. Suleiman1 ; V. S. Morozov2 ; Ya. S. Derbenev1
1

Thomas Jefferson National Accelerator Facility

2

Oak Ridge National Laboratory

Corresponding Author: suleiman@jlab.org

We will present a new design of highly specialized small storage rings for low energy polarized
electron beams. The new design is based on the transparent spin methodology that cancels the spin
precession due to the magnetic dipole moment at any energy while allowing for spin precession
induced by the fundamental physics of interest to accumulate. The buildup of the vertical componentof beam polarization can be measured using standard Mott polarimetry that is optimal at low electronenergy. These rings can be used to measure the permanent electric dipole moment of the electron,
relevant to CP violation and matter-antimatter asymmetry in the universe, and to search for darkenergy and ultra-light dark matter.

Spin in Nuclear Reactions and Nuclei / 51

Roles of spin-dependent transitions in nuclei on astrophysicalprocesses in stars
Authors: Toshio Suzuki1 ; Michio Honma2 ; Noritaka Shimizu3 ; Takaharu Otsuka4 ; Kanji Mori5 ; Toshitaka Kajino6

1

Nihon University

2

Aizu University

3

CNS, The University of Tokyo

4

The University of Tokyo, and RIKEN

5

Fukuoka University

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6/ Book of Abstracts

Beihan University

Corresponding Author: suzuki.toshio@nihon-u.ac.jp

Due to recent advances in shell-model studies on spin modes in nuclei, precise evaluations of GamowTeller (GT) strengths become feasible and electron-capture and β-decay rates in stellar environments
have been updated.
The weak rates in sd-shell obtained with the USDB Hamiltonian are applied to nuclear Urca processes in O-Ne-Mg cores in stars with 8-10 solar masses [1,2]. The Urca processes for the nuclear
pairs with A=23 and 25 are found to be important for the cooling of the core [1].
Here, the weak rates important for the Urca processes in accreted neutron star crusts [3] are investigated. The e-capture and β-decay rates are evaluated for the nuclear pair with A=31, 31 Al ↔ 31 Mg,
in sd-pf shell and the pair with A=61, 61 V ↔ 61 Cr, in f p-gd shell. 31 Mg belongs to the island of inversion, where admixtures of sd- and f p-shells become important. Energy levels in 31 Mg are foundto be well reproduced with the use of EEdf1 interaction obtained by the extended Kuo-Krensiglowa(EKK) method [4], which can properly treat Q-box calculations in two-major shells without divergence problems. The weak rates evaluated with the EKK method prove to lead to Urca processes.
The GT strengths in 61 V is evaluated with the GXPF1J Hamiltonian [5]. The calculated strength between the ground states of 61 V and 61 Cr is found to be consistent with the recent experimental data
[6]. This suggests that the Urca process for the A=61 pair would be more moderate than considered
before. Results with an extension to the f p-gd shell-model space will be also reported.
The weak rates in fp-shell obtained with the GXPF1J are applied to nucleosynthesis in Type Ia supernova explosions [7]. The electron screening effects are taken into account [8]. Overproduction
problem of neutron-rich iron-group elements for the previous weak rates is found to be considerably
suppressed.
[1] H. Toki, T. Suzuki, K. Nomoto, S. Jones, and R. Hirschi, Phys. Rev. C 88, 015806 (2013).
[2] T. Suzuki, H. Toki, and K. Nomoto, ApJ. 817, 163 (2016).
[3] H. Schatz, S. Gupta, P. Moller et al., Nature 50, 62 (2014).
[4] N. Tsunoda, T. Otsuka, N. Shimizu, M. Hjorth-Jensen, K. Takayanagi, and T. Suzuki, Phys. Rev.
C 95, 021304 (R) (2017).
[5] M. Honma et al., J. Phys. Conf. Ser. 20, 7 (2005).
[6] W. J. Ong et al., Phys. Rev. Lett. 125, 262701 (2020).
[7] K. Mori et al„ M. A. Famiano, T. Kajino et al., ApJ. 863, 176 (2018);[8] K. Mori, T. Suzuki, M. Honma et al., ApJ 904, 29 (2020).

Plenary Presentations / 52

Electric Dipole Moment Measurements at Storage Rings
Author: Joerg Pretz1
1

Forschungsyentrum Juelich Germany/RWTH Aachen University

Corresponding Author: pretz@physik.rwth-aachen.deElectric Dipole Moments (EDMs) of elementary particles, including hadrons, areconsidered as one of the most powerful tool to study CP-violation beyond the Standard Model.
Such CP-violating mechanisms are searched for to
explain the dominance of matter over anti-matter in our universe.
The talk will discuss EDM searches of charged hadrons in storage rings.
Due to an EDM, the spin vector will experience a torqueresulting in a change of the original spin direction which can be
determined with the help of a polarimeter.
Although the principle of the measurement is simple,
the smallness of the expected effect makes this a challenging experimentrequiring new developments in various experimental areas.
Given the complexity of the project, a step wise approach is proposed1) .
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The 24th International Spin Symposium/ Book of Abstracts

The talk will discuss activities at the existing storage ring COSY at Forschungszentrum J\”ulich,
Germany.
The next step is the design of a 100\,m circumference prototype ring able to demonstrate
key technologies and components. These include simultaneous clockwise and counter-clockwise
beam operation
with electrostatic bending elements and, by adding a magnetic field, the frozen spin technique.
The final step is the operation of a pure electric storage ring of about 500\,m circumference.
Other projects like a measurement of the muon EDM will also be discussed.
Storage ring to search for electric dipole moments of charged particles, Feasibility study , CPEDM
collaboration, https://doi.org/10.23731/CYRM-2021-003

1)

Low energy spin physics with lepton, photon and hadron probes / 53

Coherent neutral-pion and eta-meson photoproduction on the
deuteron
Author: Takatsugu Ishikawa1
1

Research Center for Electron Photon Science, Tohoku University

Corresponding Author: ishikawa@lns.tohoku.ac.jp

The ηd threshold structure Dηd with a spin parity of 1− has been experimentally studied in theγd → π 0 ηd reaction at Eγ 1.15 GeV. The structure is connected to the isoscalar S-wave two-bodysystem between the nucleon N and nucleon resonance N (1535)1/2− , or the chiral partner candidate of N . By incorporating the known isovector resonance D12 with a spin-parity of 2+ in the π 0 dchannel, we decompose the ηd and π 0 d invariant-mass spectra into the ηD12 and π 0 Dηd contributions. From the analysis of π 0 and η angular distributions, we determine the spin-parity of the firstintermediate ηD12 and π 0 Dηd systems. The spin-parity of the major component is found to be 0−
in the π 0 Dηd system, suggesting that some nucleon resonance contributes to π 0 η photoproduction
on the nucleon. It should be noted that ∆(1700)3/2− is the main contributor for the elementary
π 0 η photoproduction. The talk will be based on [T. Ishikawa et al., arXiv:2105.10887].

Nucleon Helicity Structure / 54

Helicity quasi-PDFs in a large Nc nucleon
Authors: Hyeon-Dong Son1 ; Maxim Polyakov1 ; Asli Tandogan1
1

Ruhr-University Bochum

Corresponding Author: hyeon-dong.son@rub.de

We discuss the properties of the helicity quark quasi-distributions in the large Nc limit. Within
the framework of the chiral quark-soliton model, we review the properties of the quasi-PDFs suchas the sum rules and the positivity. Numerical results for quark and antiquark isovector helicity
distributions are presented. Significant antiquark flavor asymmetry is observed in a wide range of
nucleon momentum.

Nucleon Helicity Structure / 55

Illuminating the nucleon spin
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The 24th International Spin Symposium/ Book of Abstracts

Author: Miguel Echevarria1
1

Universidad de Alcalá

Corresponding Author: m.garciae@uah.es

I will discuss the extension of the nucleon spin sum rule to QCDxQED. I will present the QED
corrections to the evolution of the quark and gluon helicity and orbital-angular-momentum (OAM)
distributions, which are calculated for the first time, and the necessary inclusion of photon and
lepton helicity and OAM distributions.

Transverse Momentum Structure (TMD) / 56

Transverse Spin
√ Transfer of Λ and Λ Hyperons in Polarized p+p
Collisions at s = 200 GeV at RHIC-STAR
Author: Yike XuNone
Corresponding Author: yxu@rcf.rhic.bnl.gov

The transverse spin transfer, DT T , of Λ and Λ hyperons in p+p collisions is expected to be sensitive
to the s and s̄ quark transversity distributions in the proton and to the transversely polarized fragmetation functions. The STAR experiment has published the first measurement√ of the transverse
spin transfer of Λ and Λ hyperons in transversely polarized p+p collisions at s = 200 GeV within
pseudo-rapidity |η| < 1.2 and for the transverse√momenta up to 8 GeV/c based on the data taken in2012. In 2015, a data sample of p+p collisions at s = 200 GeV, about two times larger than the 2012
data, was collected. The preliminary result of the transverse spin transfer, DT T , of Λ and Λ hyperon
versus transverse momentum, based on 2015 data, will be presented. The status of investigating
DT T versus fractional momentum of the hyperon within a jet will also be reported.

Transverse Momentum Structure (TMD) / 57

Longitudinal and transverse polarizations of Λ hyperons in unpolarized SIDIS and e+ e− annihilations
Author: Shu-yi Wei1
1

ECT* / Shandong University

Corresponding Author: shu-yi.wei@polytechnique.edu

We make a systemic study on the longitudinal polarization and two transverse polarizations of theΛ hyperons produced in unpolarized SIDIS and e+ e− annihilation.
Recently, Belle collaboration measured the transverse polarization (PN ) of Λ hyperons in e+ e−⊥annihilation [1], which inspired three parameterizations of the D1T(z, pT ) fragmentation function[2-3] so far. Unlike the other two (DMZ and CKT parameterizations) [2], for the first time, our work
(CLPSW parameterization) shows that the Belle data does not endorse isospin symmetry violation[3]. The future EIC experiment has the ability to change the target nucleons/nuclei. It can eventually
test the isospin symmetry of the polarized fragmentation functions. We make predictions for thetransverse polarization (PN ) of Λ with all three parameterizations in ep and eA scatterings. We
obtain almost no nuclear modification effect with the isospin symmetric CLPSW parameterization
at large-x. However, there is a distinct difference between the results for ep and eA scatterings in theisospin-symmetry-violating DMZ and CKT parameterizations. Therefore, the future EIC experimentcan help distinguish different parameterization scenarios and ultimately solve this dispute.
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Furthermore, the transverse polarization of the struck quark can be induced by the Boer-Mulders
function from an unpolarized hadron. This transverse polarization will further translate to azimuthal
asymmetries and polarizations of final state hyperons through chiral-odd fragmentation functions.
Therefore, besides PN , the Λ hyperons produced in unpolarized SIDIS are also polarized along thelongitudinal direction (PL ) and the transverse direction inside the production plane (PT ). These twopolarizations are azimuthal angle dependent. They disappear in the whole phase space average over
the azimuthal angle. We present how to measure these polarizations in the future EIC and the current
Belle experiments. We demonstrate their relations with the corresponding structure functions andthe leading twist fragmentation functions [4].
Our study bridges the experimental observables to the polarized fragmentation functions. The future
measurement at EIC and Belle can significantly improve our understanding of the hadronization
mechanism.
References[1] Belle Collaboration, Phys. Rev. Lett. 122 (2019), 042001 [arXiv:1808.05000].
[2] U. D’Alesio, F. Murgia and M. Zaccheddu, Phys. Rev. D 102 (2020), 054001 [arXiv:2003.01128]; D.
Callos, Z.B. Kang and J. Terry, Phys. Rev. D 102 (2020), 096007 [arXiv:2003.04828].
[3] K.B. Chen, Z.T. Liang, Y.L. Pan, Y.K. Song and S.Y. Wei, Phys. Lett. B 816 (2021), 136217 [arXiv:2102.00658].
[4] K.B. Chen, Z.T. Liang, Y.K. Song and S.Y. Wei, arXiv:2108.07740.

Plenary Presentations / 58

Spin Physics Detector at NICA
Author: Vladimir Ladygin1
1

JINR

Corresponding Author: vladygin@jinr.ru

The Spin Physics Detector (SPD) is one of the two large setups at the
NICA collider under construction at JINR (Dubna). The ultimate goal of
the studies at SPD is measurement of different spin observables inpolarized proton-proton, deuteron-deuteron and proton-deuteroncollisions sensitive to the polarized gluonic structure of the nucleon
at the luminosity up to 10^32 cm^-2*s^-1 and \sqrt{s} up to 27 GeV.
SPD will consist of the superconducting magnetic system, silicon
tracker based on the DSSD and MAPS technologies, straw mini-drift
tubes tracker, time-of-flight system, electromagnetic «shashlyk»-type
calorimeter, muon (range) and local-polarimetry systems. The highperformance free-streaming DAQ system will be able to operate at thecollision rate up to 4 MHz.

Spin in Nuclear Reactions and Nuclei / 59

Deuteron analyzing powers Ay, Ayy and Axx in dp- elastic scattering at large transverse momenta
Author: Vladimir Ladygin1
1

JINR

Corresponding Author: vladygin@jinr.ru

The results on the vector Ay and tensor Ayy and Axx analyzing powers in deuteron-proton elastic scattering at large transverse momenta are presented. These data were obtained at internal
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The 24th International Spin Symposium/ Book of Abstracts

target at JINR Nuclotron in the energy range 400-1800 MeV using polarized deuteron beam fromnew polarized ion source. New data on the deuteron analyzing powers in the wide energy range
demonstrate the sensitivity to the short-range spin structure of the isoscalar nucleon-nucleon correlations.

Joint BSM - Accelerator - Future Session EU timezone / 60

Development of Iron Thin Films for Polarization Analysis of Ultracold Neutrons
Authors: Hiroaki Akatsuka1 ; Masahiro Hino2 ; TUCAN collaborationNone
1

Nagoya University

2

KURNS

Corresponding Author: akatsuka@phi.phys.nagoya-u.ac.jp

The TRIUMF Ultra-Cold Advanced Neutron (TUCAN) collaboration aims to measure the neutron
electric dipole moment (EDM) with a sensitivity of 10−27 e·cm with a high-intensity ultracold neutron (UCN) source. Our target accuracy is an order-of-magnitude improvement over the current
best experimental limit of the neutron EDM [1]. In the neutron EDM measurement, the Larmor
precession frequency of UCNs stored in a cell under a magnetic and an electric fields is measured
by Ramsey’s technique of separately oscillating fields [2]. One of the essential steps of this measurement is polarization analysis of the UCNs, which is done by a polarization analyzer consisting of aniron thin film surrounded by a permanent magnet, and a UCN detector.
We are developing iron thin films for the polarization analyzer. They are required to have highsaturation magnetizations and low coercivities. We produce ones with lower coercivities than thoseused in previous studies [3]. The advantages of them are that the leakage magnetic field can be
reduced, and that the detector can be easily enlarged. We have characterized thin iron films producedby the ion beam sputtering facility [4] at the Institute of Combined Nuclear Science, Kyoto University,
by neutron reflectivity measurements at J-PARC BL05 and vibrating sample magnetometry. In thistalk, the results of these characterization measurements will be presented.
[1] C. Abel et al., Phys. Rev. Lett. 124, 081803 (2020).
[2] N. F. Ramsey, Phys. Rev. 78, 695 (1950).
[3] S. Afach et al., Eur Phys J. A 51, 143 (2015).
[4] M. Hino et al., Nucl. Inst. Meth. A 797, 265 (2015).

Joint GPD - Helicity session / 61

Longitudinal Spin Transfer to Lambda Hyperons in CLAS12
Author: Matthew McEneaney1
1

Duke University

Corresponding Author: matthew.mceneaney@duke.edu

Using the self analyzing decay of the Λ0 , the longitudinal spin transfer DLL from a polarized electron
beam scattering an unpolarized proton target to the hyperon can be measured. For Λ’s produced in
the current fragmentation region, this quantity is proportional to the helicity dependent fragmenta0
tion function GΛ
1 and can provide insight into the spin structure of the Λ . Currently, experimental
data on DLL is limited and is not able to discriminate between different models of the Λ0 spin structure. This contribution will report the status of the ongoing analysis of the longitudinal spin transfer
using data taken by the CLAS12 experiment at Jefferson Lab, a large acceptance spectrometer using
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The 24th International Spin Symposium/ Book of Abstracts

a 10.6 GeV electron beam. A focus of the analysis will be on the use of Graph Neural Networks(GNNs) to identify signal events.

Joint BSM - Lowenergy - Future Session US timezone / 62

The precision nEDM measurement with UltraCold Neutrons at
TRIUMF
Authors: Ryohei Matsumiya1 ; TUCAN collaborationNone
1

TRIUMF

Corresponding Author: matsumiya@triumf.ca

The TRIUMF Ultra-Cold Advanced Neutron (TUCAN) collaboration aims at a precision neutron electric dipole moment (nEDM) measurement with an uncertainty of 10−27 e·cm, which is an order-ofmagnitude better than the current nEDM upper limit [1] and enables us to test Supersymmetry. To
achieve this precision, our collaboration has been developing a new high-intensity ultracold neutron(UCN) source and a nEDM spectrometer at TRIUMF, Canada.
Recent nEDM experiments are performed by measuring the Larmor precession frequency of polarized UCNs confined in a spin precession chamber where static magnetic and electric fields areapplied. The spin precession of the UCNs in the chamber is observed by Ramsey’s technique of separately oscillating magnetic field [2]. Our nEDM spectrometer polarizes UCNs with a 3.5 T magnetic
field generated by a superconducting magnet, and then transports them through UCN guides to aspin precession chamber. The chamber is placed in a magnetically shielded room where the internal
magnetic field is controlled with high precision Cs magnetometers and compensation coils. After
flipping the UCN spin by Ramsey’s technique, the UCNs are guided from the chamber to UCN detectors. The polarization of the UCNs is analyzed by counting the number of UCNs transmitting
through magnetized iron thin films placed before the detectors.
We have been developing these sub-systems of the nEDM spectrometer. In this talk, the overview
of our project and the current development status will be presented.
[1] C. Abel et al., Phys. Rev. Lett. 124, 081803 (2020).
[2] N. F. Ramsey, Phys. Rev. 78, 695 (1950).

Joint BSM - Lowenergy - Future Session US timezone / 63

Spin tune responce to vertical orbit correction at COSY
Author: Artem Saleev1
Co-authors: Joerg Pretz 2 ; Vera Shmakova 3 ; Paolo Lenisa 4 ; Frank Rathmann 5
1

University of Ferrara

2

Forschungsyentrum Juelich Germany/RWTH Aachen University

3

Forschungszentrum Jülich

4

University of Ferrara and INFN

5

Forschungszentrum Julich, IKP

Corresponding Author: slvrtm@unife.it

Searches of electric dipole moments (EDM) of charged particles
in pure magnetic rings, such as COSY, or electrostatic and hybrid
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magnetic-electric storage rings, planned in the future, require new
methods to disentangle the EDM signal from the large backgroundproduced by magnetic dipole moments. In these experiments, thesources of systematic background are in-plane magnetic fields. It is
important to distinguish the origins of the in-plane magnetic fields,
which could be produced intentionally by vertical orbit correction tokeep the beam on a closed path, or unintentionally due to the alignment errors of the magnets. We propose to use the method of spin
tune mapping to determine the relative importance of the two origins. At
the first stage, the model of COSY should be verified for the spin tune
shifts when vertical three-steerer closed-orbit bumps are applied. At
the second stage, the spin tune responce to vertical orbit correction in
the arcs will testify its contribution to the systematic background.

Transverse Momentum Structure (TMD) / 64

Transverse Spin Dependent Azimuthal
Correlations of Charged√↑
Pion Pairs in p p Collisions at s = 200 GeV at STAR
Author: Babu Pokhrel11

Temple University

Corresponding Author: babu.pokhrel@temple.edu

At the leading twist, the transversity distribution function, hq1 (x), where x is the longitudinal momentum fraction of the proton carried by quark q, encodes the transverse spin structure of the
proton. Extraction of it is difficult because of its chiral-odd nature. However, it can be coupled
to a spin-dependent interference fragmentation function, leading to experimentally measurable azimuthal correlations, AU T , between the spin of the fragmenting quark and oppositely charged final
state hadron pairs (di-hadron). The STAR experiment
at RHIC has previously observed
non-zero√√
AU T for π + π − pairs using p↑ p collision data at s = 200 GeV from 2006 and at s = 500 GeV−1−1
from 2011, corresponding to integrated luminosities, L,√ of 1.8 pb and 25 pb , respectively. In−1↑2015, STAR collected L ∼ 52 pb √ of p p collisions at s = 200 GeV. This dataset provides highest
precision AU T measurement at s = 200 GeV to date, which covers quark momentum fractions
0.1 < x < 0.4, and is sensitive to valence quark hq1 (x). We will present preliminary results on AU T
for π + π − pairs based on this dataset.

Transverse Momentum Structure (TMD) / 65

Transverse polarization of hyperons in SIDIS from twist-3 gluon
fragmentation functions
Author: Riku Ikarashi1
Co-authors: Yuji Koike 2 ; Kenta Yabe 2 ; Shinsuke Yoshida 3
1

Niigata University, Graduate School of Science and Technology

2

Niigata University

3

South China Normal University

Corresponding Author: f21j001a@mail.cc.niigata-u.ac.jp

We study the transverse polarization of hyperons produced
in semi-inclusive deep inelastic scattering, ep → eΛ↑ X,
in the collinear twist-3 factorization. This process receives three types ofPage 27

The 24th International Spin Symposium/ Book of Abstracts

twist-3 contributions: (i) twist-3 distribution in the initial proton combinedwith the transversity fragmentation function (FF) for the hyperon,(ii) Twist-3 quark FFs for the hyperon, and (iii) Twist-3 gluon FFs for the hyperon.
In this talk, we present the twist-3 cross section for (iii) in the leading order (LO)with respect to the QCD coupling constant, which completes the LO cross section
for this process. Since gluons are ample in the nucleons, this contribution
representing multi-gluon correlations in the fragmentation process ispotentially as important as other two contributions. This study is relevant
for the future Electron-Ion Collider experiment.

Transverse Momentum Structure (TMD) / 66

Twist-3 gluon fragmentation contribution to hyperon polarization and its frame independence
Authors: Yuji Koike1 ; Kenta Yabe1 ; Shinsuke Yoshida2
1

Niigata University

2

South China Normal University

Corresponding Author: koike@phys.sc.niigata-u.ac.jp

We discuss twist-3 gluon fragmentation function (FF) contribution to the polarized hyperon production in unpolarized pp collisions. The final formula for the LO cross section is presented. Weemphasize the importance of the Lorentz invariance relations and the QCD equation-of-motion relations among the twist-3 gluon FFs to guarantee the frame independence of the twist-3 cross section.
This study is relevant for the hyperon polarization measurement at RHIC.

Applications of Nuclear Polarization in other Fields / 67

Polarization REsearch for Fusion Experiments and Reactors - The
PREFER collaboration: purposes and present status
Author: GIuseppe Ciullo1
Co-authors: M. Būscher 2 ; Ralf Engels 3 ; Marco La Cognata 4 ; Peter Rakitzis 5 ; Marco Statera 6 ; D. K. Toporkov 7 ;A. Vasilyev 8
1

INFN Ferrara and Physics and Earth Science Department of the University of Ferrara

2

PGI Forschungszentrum Jülich and H. H. University Düsseldorf, Germany

3Institute for Nuclear Physics, Research Center Juelich

4infn-lns Catania

5

FORTH-IESL and Crete University, Heraklion, Greece

6

LASA-INFN Milano, Italy

7

BINP-SBRAS, Novosibirsk, Russia

8

NRC-KI PNPI, Gatchina, Russia

Corresponding Author: ciullo@fe.infn.it

The PREFER (Polarization REsearch for Fusion Experiments and Reactors) collaboration aims to address the know-hows in different fields and techniques to the challenging bet on fusion with polarized fuel.
The efforts on a variety of duties and goals, which are under the responsibility of different institutes
and research groups (indicated here by the representatives of the research center groups in the author list).
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Starting from still open questions of fusion reaction physics, as for example the study of d-d spin dependent cross sections (Vasilyev/La Cognata) to the acceleration of polarized ions from laser-induced
plasmas (Büscher), there are many connections between the involved research groups. The collaboration is also tackling the production of nuclear polarized molecules, recombined from a polarizedatomic beam (Engels), and its cryogenic condensation and transport (Ciullo/Statera).
Other options for the production of polarized fuel are investigated in parallel, like spin separationof molecules in polarized molecular beam sources (Toporkov) or via photodissociation of molecules
into polarized hydrogen/deuterium atoms (Rakitzis).
The status of the different fields under investigation and the connections between these topics andthe different research groups will be provided.

Acceleration, Storage and Polarimetry of polarized Beams / 68

Simulations of Beam Dynamics and Beam Lifetime for the Prototype EDM Ring
Author: Andreas LehrachNone
Co-author: Saad Siddique 1
1

RWTH Aachen

Corresponding Authors: a.lehrach@fz-juelich.de, saad.siddique@rwth-aachen.de

The matter-antimatter asymmetry may be explained through CP-violation by observing a permanent electric dipole moment (EDM) of subatomic particles. An advanced approach to measure the
EDM of charged particles is to apply a unique method of “Frozen spin” on a polarized beam in an
accelerator. To increase the experimental precision step by step and to study systematic effects, theEDM experiment can be performed within three stages: the magnetic ring COSY, a prototype EDM
ring and finally all electric EDM ring. The intermediate ring will be a mock-up of the final ring,which will be used to study a variety of systematic effects and to implement the basic principle ofthe final ring. The simulations of beam dynamics of prototype EDM ring with different lattices are
performed to optimize the beam lifetime and to minimize the systematic effects. The preliminary
design of prototype EDM ring helped to estimate the beam losses by using analytical formulas. Further investigations on enhancing EDM measurement precision and reducing systematic effects arein process.

Transverse Momentum Structure (TMD) / 69

Nuclear TMDs and 3D imaging in nuclei
Author: Mishary Alrashed1
Co-authors: Daniele Anderle 2 ; Hongxi Xing 2 ; Zhong-bo Kang 1 ; john terry 1
1

UCLA

2

SCNU

Corresponding Author: johndterry@g.ucla.edu

We perform the first simultaneous global QCD extraction of the transverse momentum dependent(TMD) parton distribution functions and the TMD fragmentation functions in nuclei. We have considered the world set of data from semi-inclusive electron-nucleus deep inelastic scattering and DrellYan di-lepton production. In total, this data set consists of 126 data points from HERMES, Fermilab,
RHIC and LHC. Working at next-to-leading order and next-to-next-to-leading logarithmic accuracy,
we achieve a χ2 /dof = 1.045. In this analysis, we quantify the broadening of TMDs in nuclei comparing with those in free nucleons for the first time. We also make predictions for the ongoing JLab
12 GeV program and future EIC measurements.
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Polarized Sources and Targets / 70

Optically polarized alkali metal cell for muonic helium measurements
Author: Takashi Ino1
Co-authors: Seiso Fukumura 2 ; Patrick Strasser 3 ; Masaki Fujita 4 ; Yoichi Ikeda 4 ; Sohtaro Kanda 3 ; Masaaki
Kitaguchi 5 ; shoichiro Nishimura 3 ; Takayuki Oku 6 ; Takuya Okudaira 2 ; Hirohiko Shimizu 2 ; koichiro Shimomura
3

1

KEK

2

School of Science, Nagoya University

3

IMSS, KEK

4

IMR, Tohoku University

5

KMI, Nagoya University

6

JAEA

Corresponding Author: takashi.ino@kek.jp

Muonic helium is a helium atom with one of the two electrons substituted by a negative muon. This
three-body atomic system gives rise to opportunities to precisely study the hyperfine structure interval as well as the negative muon magnetic moment and mass. Muonic helium atoms are formed
by stopping a negative muon beam in dense helium gas, but in this formation process, the polarization of muons is lost by a factor of ten or more, remaining only several percent of the muonsspin-polarized. They can, however, be repolarized by spin-exchange collisions with polarized alkali
metal atoms [1], the same as spin-exchange optical pumping often used to polarize noble gas nuclei[2].
We are studying glass cells containing pressurized helium gas and alkali metals for muonic helium
measurements at J-PARC Muon Facility MUSE [3]. The glass cell, helium gas pressure, and polarized alkali metal density are essential to maximize the number of polarized muonic helium atoms. So
called hybrid alkali metal optical pumping, which was first developed to achieve a high 3He nuclear
polarization [4], can be applied for effective repolarization of muonic helium atoms. In the hybrid
optical pumping, Rb is optically pumped conventionally, and the Rb polarization is rapidly passed
to K atoms by spin-exchange collisions inside a cell with Rb and K enclosed together. Thanks tothe smaller spin-destruction cross section in K-K collisions compared to those between Rb atoms,
a higher alkali metal number density with a very high polarization can be obtained by the hybrid
method.
We will discuss hybrid alkali metal optical pumping cells for muonic helium measurements.
[1] A. S. Barton et al., Phys. Rev. Lett. 70, 758 (1993).
[2] T. G. Walker and W. Happer, Rev. Mod. Phys. 69, 629 (1997); T. R. Gentile, P. J. Nacher, B. Saam,and T. G. Walker, Rev. Mod. Phys. 89, 045004 (2017).
[3] P. Strasser, K. Shimomura, and H. A. Torii, JPS Conf. Proc. 21, 011045 (2018).
[4] E. Babcock et al., Phys. Rev. Lett. 91, 123003 (2003).

Acceleration, Storage and Polarimetry of polarized Beams / 71

Beam-based alignment at the Cooler Synchrotron (COSY)
Author: Tim Wagner1
1

Nuclear Physics Institute (IKP), Forschungszentrum Jülich, Germany

Corresponding Author: t.wagner@fz-juelich.dePage 30

The 24th International Spin Symposium/ Book of Abstracts

The Jülich Electric Dipole moment Investigations (JEDI) collaboration is performing a measurementof the electric dipole moment (EDM) of charged hadrons in storage rings. To perform this measurement with a high precision, it requires a small systematic error. A large contribution to thesystematic error is due to unknown magnetic fields, which are picked up when one is off of the
optimal orbit. This effect can be reduced by controlling the orbit to a high precision to a small orbit
root mean square (RMS) an thus preventing the pickup of these unknown magnetic fields.
In order to achieve a good orbit RMS in an accelerator, one needs to know the size of the offsets
between the beam position monitors (BPMs) and the quadrupoles. These offsets can be determinedwith the use of the beam-based alignment method, which finds the magnetic center of a quadrupole
with respect to the electric center of a BPM. When the offsets between the BPMs and quadrupoles
are then known, one can re-calibrate the BPMs to have the zero orbit going through the magnetic
centers of the quadrupoles. Thus, one prevents picking up extra magnetic fields, by going throughthe quadrupoles at a known, central, position instead of being at an off-center position.
The working principle of this method will be explained and the results of the beam-based alignment
measurement done at the Cooler Synchrotron (COSY) will be shown.

Joint BSM - Accelerator - Future Session EU timezone / 72

Spin-related measurements on charmed baryons at Belle
Authors: Kiyoshi Tanida1 ; for the Belle collaborationNone
1

Japan Atomic Energy Agency

Corresponding Author: tanida@post.j-parc.jp

Charmed baryons are actively studied in Belle experimentand measurements on spin-related phenomena such as
weak decay asymmetries are obtained recently.
In this talk, we will report the determination ofΞc (2970) spin-parity and the measurements ofdecay asymmetries in Ξc weak decays.
In addition, other results on charmed baryon will bepresented if time allows.

Joint GPD - Future session / 73

Exclusive production of Quarkonia and Heavy Flavors to accessgluon Generalized Parton Distributions at EIC
Authors: Tyler SchroederNone ; Marie BoerNone
Corresponding Author: tschroeder@email.wm.edu

Exclusive heavy meson production is a key tool for accessing the inner dynamics of the proton.
These reactions involve the proton Generalized Parton Distributions (GPDs), which correlate thelongitudinal momenta and their transverse distribution of the proton’s composite partons. The hard
exclusive production of Quarkonia (J/ψ, Υ, etc.) is particularly interesting, as it accesses the gluon
GPDs at the lowest order. We used ROOT to create a new flexible generator for the photoproduction,
quasi-photoproduction, and electroproduction of vector mesons off a proton. The output phase space
is weighted by the reaction cross-section, creating a realistic graph of event count as a function ofkinematics. We will discuss the relevance of measuring hard exclusive production of Quarkonia,
present our work on the event generator, and discuss our projections for the upcoming Electron-Ion
Collider (EIC).
Page 31The 24th International Spin Symposium/ Book of Abstracts

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 74

Nucleon EDM from polarized DIS
Author: Yoshitaka Hatta1
1

Brookhaven National Laboratory

Corresponding Author: yhatta@bnl.gov

I point out the connection between the matrix element of the CP-violating Weinberg operator andcertain higher-twist corrections in polarized DIS. Based on this observation I estimate the induced
nucleon EDM.

Nucleon Helicity Structure / 75

First Extraction of Polarized Sea Asymmetry from Weak Boson
Production in Proton-Proton Collisions
Authors: Christopher Cocuzza1 ; Jake Ethier2 ; W. Melnitchouk3 ; Andreas Metz1 ; N. Sato31

Temple University

2

Nikhef3

Jefferson Lab

Corresponding Author: tug83224@temple.edu

We present the first global QCD analysis of helicity parton distribution functions (PDFs) to include
the latest polarized W -lepton production data from the STAR collaboration at the Relativistic HeavyIon Collider. This data allows the first extraction of a nonzero helicity light quark sea asymmetry
within a global QCD analysis. By performing a simultaneous extraction of the unpolarized and helicity PDFs, we are also able to extract for the first time in a self-consistent manner the polarizations¯ d.
¯of the light sea quarks ∆ū/ū and ∆d/Joint TMD - GPD - HELCITY - Future session EU timezone / 76

The gT(x) contribution to single spin asymmetry in SIDIS
Authors: Sanjin BenicNone ; Yoshitaka Hatta1 ; Abhiram Kaushik2 ; Hsiang-nan Li3
1

Brookhaven National Laboratory

2

University of Zagreb

3

Institute of Physics, Academia Sinica, Taipei

Corresponding Author: sanjinb@phy.hr

I will talk about our recent computation [1] of a gT(x) contribution to transverse single spin asymmetry (SSA) in SIDIS in a collinear framework. In [1] we have found that gT(x) first appears at two-loops.
I will explain main steps of our calculation and show the final formula for the cross section [2] in the
Wilczek-Wandzura (WW) approximation, that is, neglecting the genuine twist-3 pieces. In the WW
approximation gT(x) is given as an integral of the helicity distribution, which is known from global
fits. In this way, an explicit evaluation of SSA has no free parameters in principle. I will show ourresults from an extensive numerical computation for the spin dependent moments A_UT, such as
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Sivers and Collins moment, coming from gT [2], for the future EIC kinematics. Finally, I will makecomments about an analogue contribution in the gluon initiated channel arising from the G_3T(x)that is also included in our full numerical setup.
[1] S. B., Y. Hatta, H-n. Li, D.-J. Yang, Phys. Rev. D 100 (2019) 9, 094027[2] S. B., Y. Hatta, A. Kaushik, H.-n. Li, in preparation

Joint GPD - Helicity session / 77transverse spin sum rules
Author: XIANGDONG JI1
1

University of Maryland

Corresponding Author: xji@umd.edu

There are two transverse spin sum rules for the proton: One involves twist-2 GPDs, which has apartonic interpretation, and the other involves twist-3 distributions including the well-know spin
structure function g_2. I will explain the origin and physics of these two spin sum rules.

Polarized Sources and Targets / 78

New application of a Sona transition unit: Observation of directtransitions between quantum states with energy differences of 10
neV and below
Author: Chrysovalantis Kannis1
Co-authors: Ralf Engels 2 ; Christoph Hanhart 3 ; Helmut Soltner 4 ; Lukas Huxold 3 ; Kirill Grigoryev 3 ; Andreas
Lehrach ; Markus Būscher 5 ; Thomas Sefzick 6
1

Forschungszentrum Jülich

2

Institute for Nuclear Physics, Research Center Juelich3Institut für Kernphysik, Forschungszentrum Jülich, Jülich, Germany

4

Zentralinstitut für Engineering, Elektronik und Analytik, Forschungszentrum Jülich, Jülich, Germany

5

PGI Forschungszentrum Jülich and H. H. University Düsseldorf, Germany

6

Institut für Kernphysik, Forschungszentrum Jülich

Corresponding Author: c.kannis@fz-juelich.deFor more than 50 years Sona transition units have been used at polarized sources to exchange theoccupation numbers between ‘pure’ hyperfine substates. For instance, hydrogen atoms in the hyperfine substate |F = 1, mF = +1⟩ are transferred into |F = 1, mF = −1⟩ when these atoms
are passing a static magnetic field gradient between two opposing solenoidal magnetic fields. Thus,
the magnetic field direction, i.e. the quantization axis, is rotated faster than the spin orientation canfollow due to the Larmor precession.
In parallel, the atoms traveling through the zero crossing of the static magnetic field experiencein their rest frame an oscillating magnetic field. This oscillation is equivalent to an external radio
frequency field of frequency f = vatom /λ that can induce transitions between hyperfine substateswith the energy difference ∆E = h · n · f , where n is an integer. Here, the distance between the
opposite coils determines the wavelength λ, thus the beam velocity vatom can be used to manipulate
the frequency f to induce transitions between quantum states with energy differences of 10 neV andbelow. These tiny energy differences can be found between hyperfine substates of hydrogen atoms
at low magnetic fields in the Breit-Rabi diagram. In this talk first measurements, their interpretationand possible applications will be presented.
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Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 79

The search for electric dipole moments of charged particles using
storage rings
Author: Vera Shmakova1
1

Forschungszentrum Jülich

Corresponding Author: v.shmakova@fz-juelich.de

One of the major problems of modern particle physics is the inability of the Standard Model (SM) of
Particle Physics to explain the matter-antimatter asymmetry in the Universe. Therefore, the pursuitof physics beyond the SM is required and one of the necessary conditions for the appearance ofthe matter-antimatter asymmetry is the violation of the CP symmetry. Permanent electric dipole
moments (EDMs) of particles violate both time reversal and parity invariance and, via the CPTtheorem they also violate the combined CP symmetry. Hence, EDM measurements of fundamental
particles are capable to probe new sources of CP-violation.
Storage rings provides possibility to measure EDMs of charged particles by observing the effect of the
EDM on the spin motion in the ring. The Cooler Synchrotron COSY at the Forschungszentrum Jülich
provides polarized protons and deuterons with momenta up to 3.7 GeV/s, which is an ideal testing
ground and starting point for the JEDI collaboration (Jülich Electric Dipole moment Investigations)for such an experimental program.
The talk will present recent results of the first direct (precursor) measurements of the deuteron EDM
in COSY.

Joint TMD - GPD - HELCITY - Future session US timezone / 80

Back-to-back proton-pi+ correlations with CLAS12
Authors: Timothy Hayward1 ; Harut Avakian2
1

University of Connecticut

2

Jefferson Lab

Corresponding Author: timothy.hayward@uconn.edu

We report preliminary results from the first measurement of a novel beam-spin asymmetry involving the back-to-back production of a target-fragmentation proton and current-fragmentation π + .
Non-zero sin ∆ϕ moments for the semi-inclusive deep inelastic scattering process, ep → P π + X,
where the ∆ϕ is the difference of azimuthal angles between the two hadrons, indicate that spin-orbit
correlations between target and current fragments may be significant. The dependence of the modulation on the product of transverse momenta of two hadrons is consistent with predictions basedon the fracture function formalism. Data was taken with the upgraded CLAS12 detector at Jefferson
Lab where a 10~GeV electron was scattered off of a liquid hydrogen target during two run periods
in 2018 and 2019.

Acceleration, Storage and Polarimetry of polarized Beams / 81

Spin Transparency Method for High Precision Experiments with
Polarized Beams
Authors: Yury Filatov1 ; Ya. S. Derbenev2 ; Riad Suleiman3 ; Vasiliy Morozov4 ; Anatoliy Kondratenko5 ; Mikhail
Kondratenko5 ; Andrey Butenko6 ; Evgeny Syresin7

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1

MIPT

2

Thomas Jefferson National Accelerator Facility

3

Jefferson Lab

4

Oak Ridge National Laboratory

5

Science and Technique Laboratory ”Zaryad”

6

Joint Institute for Nuclear Research

7

JINR

/ Book of Abstracts

Corresponding Author: filatov.iun@mipt.ru

The Spin Transparency technique is discussed as an efficient, highly flexible method for control of thebeam polarization. It applies from acceleration to long term maintenance and spin manipulation inreal time during an experimental run of a collider or storage ring. This method relies on “transparent”
collider structures where, for a particle moving on the design orbit, any initial orientation of its spin
is repeated every turn at any location along the orbit. Precision control of the spin direction andthe spin tune is accomplished using “spin navigators” based on weak longitudinal and transverse
magnetic fields. Spin navigators can be used to compensate the effects of field errors as well as toreverse the spins multiple times during an experiment. This allows one to substantially reduce theexperiment’s systematic errors and reach a new level of measurement precision. The main featuresof the spin transparency mode are demonstrated using the examples of a figure-8 collider, a racetrackwith two identical Siberian snakes, as well as a conventional ring at an energy corresponding to an
integer spin resonance. We demonstrate the feasibility of low-energy figure-8-based rings dedicatedto search for Electric Dipole Moment and Dark Matter. We consider the possibility of applying thespin transparency mode at ultra-high energies.

Future facilities and experiments / 82

Neutron Spin Structure from e-3He Scattering with Double Spectator Tagging at the Electron-Ion Collider
Author: Jackson Pybus1
1

MIT

Corresponding Author: jrpybus@mit.edu

This spin structure function of the neutron is traditionally determined by measuring the spin asymmetry of inclusive electron deep-inelastic scattering (DIS) off polarized 3 He nuclei. In such experiments, correcting for nuclear effects can introduce large systematic uncertainties and modeldependencies. This talk presents our study of the feasibility of suppressing such model dependencies by tagging both spectator protons in the process of DIS off neutrons in 3 He at the forthcoming
Electron-Ion Collider (EIC). This allows us to reconstruct the momentum of the struck neutron toensure it was nearly on-shell in the initial state, thereby reducing sensitivity to nuclear corrections,and to suppress contributions from electron DIS off protons in 3 He. We find that the EIC can probe
the neutron spin structure from xB of 0.003 to 0.0651. We further find that the double spectator
tagging method results in reduced uncertainties by a factor of 4 on the extracted neutron spin asymmetries over all kinematics, and by a factor of 10 in the low-xB region, providing high-precision
data that will give insight into the spin structure of the nucleon.

Nucleon Helicity Structure / 83Studies of Neutral Current Neutrino-Nucleon Scattering with theMicroBooNE Detector
Author: Lu Ren1

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1/ Book of Abstracts

New Mexico State University

Corresponding Author: renlu23@nmsu.edu

The MicroBooNE experiment is an 85 ton active volume liquid-argon time projection chamber (LArTPC)
located in the Booster Neutrino Beamline at Fermilab. The excellent calorimetric and spatial resolution of the LArTPC allows us to identify isolated proton tracks with lengths as short as 2 cm, whichis equivalent to proton kinetic energy T = 50 MeV. We report the progress towards the first measurement of muon neutrino neutral current elastic scattering from protons in Argon in the region of
four-momentum transfer squared, 0.1 < Q2 < 1 GeV2 , using MicroBooNE’s 6.87×1020 POT data.
We also present our plan to extract the strange quark contribution to the axial form factor, which is
crucial for understanding the strange quark contribution to the proton spin.

Transverse Momentum Structure (TMD) / 84

Polarized Drell-Yan experiment at Fermilab, SpinQuest (E1039)
Author: Yoshiyuki Miyachi1
1

Yamagata University

Corresponding Author: miyachi@sci.kj.yamagata-u.ac.jp

E1039/SpinQuest is a polarized fixed-target Drell-Yan experiment using the 120 GeV proton beamfrom the Main Injector at Fermilab. The primary goal of SpinQuest is to measure the Sivers asymmetries, aiming to shed light on the fundamental question, “Do the light sea quarks contribute to theintrinsic spin of the nucleon via their orbital angular momentum?”. The Sivers asymmetry was first
introduced to explain the unexpected, significant, transverse, single-spin asymmetries observed in
the hadron-scattering. The Sivers functions for u and d quarks have been measured and found tobe similar in size but with the opposite sign, but there are no data available yet for the sea quarks
Sivers functions. SpinQuest will determine the ū and d¯ Sivers asymmetries in Drell-Yan using thetransversely polarized proton and deuteron targets for the first time. The overview of SpinQuest,
including the recent progress toward physics data taking, will be presented.

Polarized Sources and Targets / 85

Dilution factor calculation and its contribution to SpinQuest systematic error
Author: Anchit Anchit AroraNone
Corresponding Author: aa6nc@virginia.edu

The spin of the nucleon is well established but the contribution to this intrinsic value from its constituent partons is still under intense investigation. As part of a global effort to map out these
individual contributions, the SpinQuest experiment at Fermilab aims to add significantly to the levelof information available on sea-quarks by measuring their Sivers function. To separate the contributions of u bar and d bar quarks to the Sivers asymmetry, the experiment uses both NH3 and ND3
polarized targets, interacting with an incoming unpolarized 120 GeV/c proton beam. The dimuons
from the Drell-Yan process are detected to analyze the azimuthal asymmetry. The incoming proton
beam will also interact with other materials that are present in the experimental beam path, such as
the target cell walls, the aluminum insert ladder, the microwave horn, liquid helium and nitrogenin the ammonia target. The figure of merit in our extracted Sivers function is directly dependent
on both the magnitude of polarization and the interaction rate from these various unwanted materials resulting in a dilution factor. With the use of MCFM (Monte Carlo simulation at femtobarn),a par- ton distribution based cross-section generator we can analyze the contributions from unmeasured cross-section from these various materials to find the degree of dilution and the corresponding
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kinematic sensitivity. This contribution to the experimental systematic error and its management isreviewed in this presentation.

Plenary Presentations / 86

Dipole polarizability from small-angle proton scattering and implications for symmetry energy properties and the formation ofneutron skins
Author: Peter von Neumann-Cosel1
1Institut fur Kernphysik, TU Darmstadt

Corresponding Author: vnc@ikp.tu-darmstadt.de

The dipole polarizability of nuclei carries information on the density dependence of the symmetryenergy governing the properties of the Equation of State of neutron-rich matter relevant to neutronstars and core-collapse supernovae. In recent years, zero-degree polarized proton scattering has
been developed at RCNP as an experimental tool to measure the dipole polarizability [1]. Such dataalso provide constraints on the neutron skin thickness of heavy nuclei [2]. A recent study of 40 Ca
together with results from a previous experiment on 48 Ca [3] serve as a test of state-of-the-art abinitio [4,5] and energy densitiy functional [6] calculations. From the good agreement obtained forboth methods one can set limits on the density dependence of the symmetry energy. These are clearlyat variance with those derived [7] from the recently published result of the PREX-II experiment[8].
[1] P. von Neumann-Cosel and A. Tamii, Eur. Phys. J. A 55, 110 (2019).
[2] A. Tamii et al., Phys. Rev. Lett. 107, 262502 (2011).
[3] J. Birkhan et al., Phys. Rev. Lett. 118, 252501 (2017).
[4] J. Simonis, S. Bacca, and G. Hagen, Eur. Phys. J. A 55, 241 (2019).
[5] S. Kaufmann et al., Phys. Rev. Lett. 124, 132502 (2020).
[6] P.-G. Reinhard, X. Roca-Maza, and W. Nazarewicz, arXiv:2105.15050.
[7] B.T. Reed, F.J. Fattoyev, C.J. Horowitz, and J. Piekarewicz, Phys. Rev. Lett. 126, 172503 (2021).
[8] D. Adhikari et al., Phys. Rev. Lett. 126, 172502 (2021).

Joint TMD - GPD - HELCITY - Future session US timezone / 87

Global Analysis of SSAs and the Impact of the EIC on Tensor
Charge Extractions
Authors: Alexei ProkudinNone ; Daniel PitonyakNone ; Leonard GambergNone ; Nobuo SatoNone ; Ralf Seidl1 ; Zhongbo
KangNone
1

RIKEN

Corresponding Author: prokudin@jlab.org

We perform the first simultaneous QCD global analysis of data from semi-inclusive deep inelastic scattering, Drell-Yan, e+e- annihilation into hadron pairs, and proton-proton collisions. Consequently, we are able to extract a universal set of nonperturbative functions that describes theobserved asymmetries in these reactions. The outcome of our analysis indicates single transversespin asymmetries in high-energy collisions have a common origin. We study the impact of theElectron-Ion Collider (EIC) on the phenomenological extraction of the tensor charge from a QCD
global analysis of single transverse-spin asymmetries (SSAs). We generate EIC pseudo-data for the
Collins effect in semi-inclusive deep-inelastic scattering for proton and H3e beams across multiple
center-of-mass energies. We find a significant reduction in the uncertainties for the up, down, andPage 37

The 24th International Spin Symposium/ Book of Abstracts

isovector tensor charges that will make their extraction from EIC data on SSAs as precise as current
lattice QCD calculations. We also analyze the constraints placed by future data from the proposed
SoLID experiment at Jefferson Lab, discuss its important complementary role to the EIC, and present
the combined impact from both facilities.

Nucleon Helicity Structure / 88

Collinear twist-3 approach to hyperon polarization in SIDIS
Author: Kazuki Takada1
Co-authors: Yuji Koike 1 ; Sumire Usui 2 ; Kenta Yabe 1 ; Shinsuke Yoshida 1
1

Niigata University

2

Niigata university

Corresponding Author: f20j009b@mail.cc.niigata-u.ac.jp

We discuss the production of transversely polarized hyperons in semi-inclusive deep inelastic scattering in the framework of the collinear twist-3 factorization. In this framework, the twist-3 crosssection consists of three contributions depending on the origins for the polarizations: (i) Twist-3
distribution in the initial proton combined with the twist-2 transversity fragmentation function (FF)for the final hyperon, (ii) Twist-3 quark FF for the hyperon and (iii) Twist-3 gluon FF for the hyperon.
In this talk. we focus on the first two contributions, since they are expected to become dominant
contribution. We present the twist-3 cross section in the leading order (LO) with respect to the QCD
coupling constant for all the five structure functions which have different dependences on the azimuthal angles. We also discuss the matching with the TMD framework in the small-PT region. The
present result is important for the future EIC experiment.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 89

Towards a surrogate computational tool to quantify the systematic uncertainties in EDM experiments in storage rings
Author: Jamal Slim1
1

RWTH Aachen University

Corresponding Author: slim@physik.rwth-aachen.de

The searches for permanent Electric Dipole Moments (EDMs) of elementary
particles provide a powerful tool to probe physics beyond the standard model(SM). This is particularly useful to investigate the CP-violation mechanismsthat can explain the matter-antimatter asymmetry in the universe.
Conducting such searches in storage rings requires unprecedented understanding of beam and spin dynamics, dictated by the smallness of the EDM signal
to be measured. Given the complexity of storage rings, the desired signal ismainly dominated by the systematic uncertainties of the machine. It is therefore mandatory to build a computational model that emulates the realistic
machine in order to help to disentangle the real signal out of the fake one.
This talk will present a surrogate computational tool in the context of spin andbeam dynamics, to quantify the hierarchy of uncertainties in a storage ring.
This tool will be applied to a model of the Cooler Synchrotron (COSY) as a
proof-of-principle.

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Joint TMD - GPD - HELCITY - Future session US timezone / 90

Time-reversal Odd Side of a Jet
Authors: Wai Kin Lai1 ; Hongxi Xing2 ; Xiaohui Liu3 ; Manman Wang3
1

South China Normal University

2

SCNU

3

Beijing Normal University

Corresponding Author: wk.lai@tum.de

We re-examine the jet probes of the nucleon spin and flavor structures. We find for the first timethat the time-reversal odd (T-odd) component of a jet, conventionally thought to vanish, can survive
due to the nonperturbative fragmentation and hadronization effects. This additional contributionof a jet will lead to novel jet phenomena relevant for unlocking the access to several spin structuresof the nucleon, which were thought to be impossible by using jets. As examples, we show how theT-odd constituent can couple to the proton transversity at the Electron Ion Collider (EIC) andcan give rise to the anisotropy in the jet production in e+ e− annihilations. We expect the T-odd
contribution of the jet to have broad applications in high energy nuclear physics.

Nucleon Helicity Structure / 91

Small-x Helicity Evolution and the Proton Spin Puzzle
Authors: Daniel PitonyakNone ; Daniel Adamiak1 ; Yuri Kovchegov1 ; Wally Melnitchouk2 ; N. Sato2 ; Matt Sievert3

1

Ohio State University2

Jefferson Lab

3

New Mexico State

Corresponding Author: pitonyak@lvc.edu

We report on the first phenomenological analysis of the world polarized deep-inelastic scattering(DIS) data incorporating small-x helicity (Kovchegov-Pitonyak-Sievert) evolution. This framework
allows for one to predict the behavior of helicity parton distribution functions (PDFs) down to very
low x. Consequently, one can control the uncertainties in these functions beyond the measured
region and make precise calculations of the integrals needed to determine the contribution of quarkand gluon spin to the proton spin. Therefore, the small-x helicity formalism will play a crucial rolein using future Electron-Ion Collider data to resolve the proton spin puzzle.

Transverse Momentum Structure (TMD) / 92

Transverse single-spin asymmetries of W±-bosons in p+p collisions at √s = 510 GeV
Authors: K. Oleg Eyser1 ; STAR CollaborationNone
1

UC Riverside

Corresponding Author: keyser@bnl.gov

The STAR experiment at RHIC has measured transverse single-spin asymmetries of W±-bosons in
proton-proton collisions at a center-of-mass energy √s = 510 GeV (2017 data). These asymmetries
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probe correlations between parton motion and the proton spin in the initial state which are described in terms of transverse momentum dependent parton distribution functions (TMD), in thiscase the Sivers function. The Sivers function is of particular theoretical interest because its processdependence can be linked to underlying kinematics, namely the gauge link structure of the scatteredparton with the nucleon remnant. This means that the Sivers function is not universal and a signchange is expected between the asymmetries measured in semi-inclusive deep inelastic scattering
compared to those in hadronic collisions. The new STAR preliminary results with an integrated luminosity of about 350 pb−1 improve significantly on previous data from 2011. We will discuss details of
the full reconstruction of the W-boson kinematics which are required for a true TMD measurement.
Comparison with recent global fits will illustrate the potential impact of the new data.

Joint BSM - Lowenergy - Future Session US timezone / 93

Evolution of primordial neutrino helicities in cosmic magnetic
fields and gravitational inhomogeneities
Author: Gordon Baym1
Co-author: Jen-Chieh Peng 1
1

University of Illinois

Corresponding Authors: jcpeng@illinois.edu, gbaym@illinois.edu

Primordial neutrinos decoupled in the early universe predominantly in helicity eigenstates. Their
subsequent propagation through the residual cosmic and galactic magnetic fields partially flips theirhelicities.[1] In view of the possibility of large neutrino magnetic moments arising from beyondthe-standard-model physics – e.g., as the XENON1T experiment reported as a possible explanationof their low energy event excess – we estimate the magnitudes of the helicity flips for relic Diracneutrinos both in galactic and cosmic magnetic fields. Majorana neutrinos would not undergo such
flips. The helicity flip probability is sensitive not only to the magnetic moment of neutrinos but
also to the properties of galactic and cosmic fields, and thus can thus potentially probe astrophysicalmagnetic fields. We find that even a moment several orders of magnitude smaller than that possibly
found by XENON1T could lead to significant helicity changes of Dirac neutrinos as they propagate
to detectors on Earth. We also discuss the effects of gravitational inhomogeneities on the helicity ofprimordial neutrinos.[2][1] G. Baym and J. C. Peng, Phys. Rev. Lett. 126, 191803 (2021).
[2] G. Baym and J. C. Peng, Phys. Rev. D 103, 123019 (2021).

Joint BSM - Lowenergy - Future Session US timezone / 94

Primordial neutrino helicity modification in magnetic and gravitational fields and implications for their detection
Authors: Jen-Chieh Peng1 ; Gordon BaymNone
1

University of Illinois at Urbana-Champaign

Corresponding Author: jcpeng@illinois.edu

The evolution of primordial neutrino helicities in cosmic magnetic fields and gravitational inhomogeneity has been studied recently [1,2]. Detection of relic neutrinos from the Big Bang, e.g., throughthe inverse tritium beta decay reaction (ITBD) in the PTOLEMY experiment, remains a major challenge. We examine the implications of the helicity properties of the relic neutrinos on their detectionin ITBD. While the ITBD rate is insensitive to the helicity of Majorana neutrinos, helicity flips ofPage 40

The 24th International Spin Symposium/ Book of Abstracts

Dirac neutrinos both via interactions with gravitational perturbations and cosmic and galactic magnetic fields does effect the ITBD detection rate for neutrino masses below ∼ 10−2 eV. However,resolving relic neutrino events from the tritium beta decay background becomes increasingly difficult with lower neutrino mass, and will require advances in electron detection techniques. We also
discuss the prospect for detecting the ITBD reaction for the first time using an intense 51 Cr neutrino
source.
1) G. Baym and J. C. Peng, Phys. Rev. Lett. 126, 191803 (2021).
2) G. Baym and J. C. Peng, Phys. Rev. D 103, 123019 (2021).

Transverse Momentum Structure (TMD) / 95

Gluon TMDs and J/ψ polarization in SIDIS
Authors: Cristian PisanoNone ; Umberto D’AlesioNone ; Luca MaxiaNone ; Francesco MurgiaNone ; Sangem RajeshNone
Corresponding Author: cristian.pisano@unica.it

We study the polarization of / mesons produced in semi-inclusive, deep-inelastic electron-proton
scattering in different reference frames at the EIC energies. At low transverse momentum, we propose factorized expressions in terms of transverse momentum dependent gluon distributions andshape functions. In particular, we show that the distribution of linearly polarized gluons can, in
principle, affect the polarization of the produced quarkonium states. We also demonstrate that ourformulae, at the order , correctly match with the collinear factorization results at high transverse
momentum.

Form Factors and GPDs / 96

Accessing pion’s large-x gluon by fixed-target charmonium production
Author: Wen-Chen Chang1
Co-authors: Jen-Chieh Peng 2 ; Stephane Platchkov 3 ; Takahiro Sawada 4
1

Institute of Physics, Academia Sinica

2

University of Illinois

3

IRFU, CEA, Universit\’{e} Paris-Saclay

4

Department of Physics, Osaka City University

Corresponding Author: changwc@phys.sinica.edu.tw

The pion, as the Goldstone boson of dynamical chiral symmetry breaking of the strong interaction, isthe lightest QCD bound state. Because of its light mass, pion plays a dominant role in the long-range
nucleon-nucleon interaction. Understanding the pion’s internal structure is important to investigate
the low-energy, non-perturbative aspects of QCD. Nevertheless, the uncertainties of partonic density
functions (PDFs) of pions are relatively huge due to lacking rest pion targets.
In this talk, we will review recent theoretical and experimental progress of extracting the pion PDFs.
Furthermore, we will provide quantitative evidence within the CEM and NRQCD frameworks thatthe existing pion-induced fixed-target J/psi data, are sensitive to the gluon density of pions, andfavor the pion PDFs with relatively large gluon contents at large x.
References[1] C.Y. Hsieh, Y.S. Lian, W.C. Chang, J.C. Peng, S. Platchkov, and T. Sawada, Chin. J. Phys. 73, 13(2021); arXiv:2103.11660.
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The 24th International Spin Symposium/ Book of Abstracts[2] W.C. Chang, J.C. Peng, S. Platchkov, and T. Sawada, Phys. Rev. D 102, 054024 (2020).Rev. D 99,
014032 (2019); arXiv:2006.06947.

Transverse Momentum Structure (TMD) / 97

TMDs for spin-1 hadrons
Authors: Shunzo Kumano1 ; Qin-Tao Song2
1

KEK

2

Zhengzhou University

Corresponding Author: shunzo.kumano@kek.jp

We explain possible transverse-momentum-dependent parton distribution functions (TMDs) for spin1 hadrons up to twist 4 by decomposing a quark correlation function with the conditions of the Hermiticity and parity invariance [1]. In the TMDs, there exist time-reversal-odd functions in addition
to the time-reversal-even ones. We showed that 40 TMDs exist in the tensor-polarized spin-1 hadronin the twist 2, 3, and 4. In particular, we found 30 new structure functions in the twist 3 and 4 inour work. Since time-reversal-odd terms of the collinear correlation function should vanish after
integrals over the partonic
we ∫obtain new sum rules for the time-reversal∫ transverse momentum,∫
odd structure functions, d2 kT gLT = d2 kT hLL = d2 kT h3LL = 0. In addition, we indicatedthat new transverse-momentum-dependent fragmentation functions exist in tensor-polarized spin-1
hadrons. The tensor structure functions may not be easily measured in experiments. However, highintensity facility such as the Thomas Jefferson National Accelerator Facility (JLab), the Fermilab Main
Injector, and future accelerators like electron-ion collider (EIC) may probe such observables. In addition, since the Nuclotron-based Ion Collider fAcility (NICA) focuses on spin-1 deuteron structure
functions, there is a possibility to study the details of polarized structure functions of the deuteronat this facility.
[1] S. Kumano and Qin-Tao Song, Phys. Rev. D 103 (2021) 014025.

Nucleon Helicity Structure / 98

Measurement of the anti-quark flavor asymmetry in the proton
at FNAL-SeaQuest
Author: Kenichi Nakano1
1

University of Virginia

Corresponding Author: knakano0524@gmail.com¯
The flavor asymmetry of the unpolarized distributions of light anti-quarks (i.e. ū(x) and d(x))
in the¯
proton was observed by several deep-inelastic muon scattering experiments. The ratio d(x)/ū(x)was measured by Drell-Yan experiments NA51 at CERN and E866 at Fermilab and a large asymmetry
was reported.
The mechanism of this asymmetry has been studied via various theoretical models. The asymmetryof unpolarized distributions can be correlated with that of helicity distributions,(e.g. the statistical)¯ − ū(x) ≈ − ∆d(x)¯ − ∆ū(x) .
model predicts the similar magnitude with the opposite sign; d(x)Therefore a comparison between the unpolarized and helicity distributions of the sea quarks is appropriate.
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SeaQuest at Fermilab is a fixed-target experiment designed to detect the Drell-Yan process in p + p¯
and p + d reactions. The goal is to measure precisely the ratio d(x)/ū(x)in a wide Bjorken x region
up to 0.45. Results from SeaQuest on the anti-quark flavor asymmetry will be presented.

Nucleon Helicity Structure / 99

Constraining the Polarized Gluon Distribution Function of theProton with Recent STAR Measurements
Author: Nick Lukow1
1

Temple University

Corresponding Author: tug65406@temple.edu

The contribution of the gluon spin to the spin of the proton is being studied through the use of theunique capabilityof the Relativistic√ Heavy Ion Collider (RHIC) to collide longitudinally polarized√
protons at s = 200 GeV and s = 510 GeV. The kinematic coverage of the Solenoidal Tracker
At RHIC (STAR) allows access to gluons through quark-gluon and gluon-gluon scattering processes
which dominate particle production at low and medium transverse momentum. The polarized gluon
distribution function, ∆g(x), can be constrained through global analyses of the longitudinal doublespin asymmetries (ALL ) of inclusive jet and di-jet production.
√
Published inclusive jet results from 2009 data at mid-rapidity (|η| < 1 ) at s = 200 GeV have been
included in global analyses and suggest a significant non-zero truncated first moment of ∆g(x)for x > 0.05. An additional data sample of 43 pb−1 has been collected in 2015 at the same collisionenergy. This new data sample is over twice as large as the previous sample, providing an opportunity
to improve the precision of ∆g(x) for x > 0.05. The published results from the analysis of the 2015
data will be √presented along with the status of the analysis using a large data sample of 250 pb−1
collected at s = 510 GeV in 2013.

Plenary Presentations / 100

The physics program at EIC: towards the realization
Author: Olga Evdokimov1
1

UIC

Corresponding Author: evdolga@uic.edu

The Electron-Ion Collider (EIC) will be the new, most sophisticated accelerator facility for studying
properties of nuclear matter at high intensity and resolving power. Nearly two decades in the planning, the EIC is now the highest priority project for new construction in the US Nuclear Physics
Long Range Plan of 2015. It is enthusiastically endorsed by the US National Academy of Sciencesin 2018. The EIC will address fundamental open questions on nucleon and nuclear structure, theorigin of mass and nucleon spin, and the emergent properties of a dense system of gluons in nuclear
matter.
To further sharpen and broaden the physics case and to evaluate experimental requirements forthe detector design capable of delivering the EIC physics goal, the EIC Users Group has organized
the Yellow Report Initiative. This intensive year-long study of planned physics measurements andrequired and available detector technologies resulted in the most comprehensive report, providing
the basis for further development of experimental setup best suited for science needs.
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In this talk, I will summarize the established EIC design capabilities and physics goals and then focus on recent progress in developments of physics measurement, corresponding experimental equipment requirements, and emerging detector concepts on the path for the realization of the EIC.

Polarized Sources and Targets / 101

Status of Lamb-shift polarized ion source at 6 MV tandem accelerator in UTTAC and its application to nuclear physics
Authors: Tetsuaki Moriguchi1 ; Akira Ozawa1 ; Yoshihiro Yamato1 ; Mika Hayashi1 ; Reo Kagesawa1 ; Naoto Kaname1 ;Momo Mukai2 ; Keisuke Tomita1 ; Asahi Yano1
1

University of Tsukuba

2

RIKEN

Corresponding Author: moriguchi@tac.tsukuba.ac.jp

A polarized ion source has contributed to the development of the nuclear physics, as represented
by the measurement of analyzing power. At University of Tsukuba Tandem Accelerator Complex(UTTAC), a Lamb-shift polarized ion source (PIS) is operated as one of the injections of 6 MV tandem accelerator. The PIS can produce highly negative polarized proton and deuteron beams. The
PIS was damaged seriously ten years ago due to the Great East Japan Earthquake, but was recovered successfully within five years. Currently, the polarized proton and deuteron beams which areaccelerated up to 12 MeV can be transported to the experimental course with approximately 100 nA
and 10 nA for proton and deuteron beams, respectively. One of application to nuclear physics is the
production of polarized unstable nuclei via polarization transfer reactions with polarized proton ordeuteron beams. Up to now, we succeeded to produce polarized unstable nuclei for 25 Al (J = 5/2+,
T1/2 = 7.183 s) and 29 P (J = 1/2+, T1/2 = 4.142 s). In addition, we observed nuclear magnetic resonances (NMR’s) of them with the beta-ray detected NMR technique. In this presentation, we willtalk about the current status of the PIS and experimental results related to the PIS.

Nucleon Helicity Structure / 102

Useful relations and sum rules for PDFs and multiparton distribution functions of spin-1 hadrons
Authors: Qin-Tao Song1 ; Shunzo Kumano2
1

Zhengzhou University

2

KEK

Corresponding Author: songqintao@zzu.edu.cn

Sum rules for structure functions and their twist-2 relations have important roles in constraining
their magnitudes and x dependencies and in studying higher-twist effects. The Wandzura-Wilczek(WW) relation and the Burkhardt-Cottingham (BC) sum rule are such examples for the polarized
structure functions g1 and g2 . Recently, new twist-3 and twist-4 parton distribution functions were
proposed for spin-1 hadrons, so that it became possible to investigate spin-1 structure functions including higher-twist ones. We show in this work that an analogous twist-2 relation and a sum rule
exist for the tensor-polarized parton distribution functions f1LL and fLT , where f1LL is a twist-2function and fLT is a twist-3 one. Namely, the twist-2 part of fLT is expressed by an integral of
f1LL (or b1 ) and the integral of the function f2LT = (2/3)fLT − f1LL over x vanishes. If theparton-model sum rule for f1LL (b1 ) is applied by assuming vanishing tensor-polarized antiquark
distributions, another sum rule also exists for fLT itself. These relations should be valuable for studying tensor-polarized distribution functions of spin-1 hadrons and for separating twist-2 components
from higher-twist terms, as the WW relation and BC sum rule have been used for investigating x
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dependence and higher-twist effects in g2 . In deriving these relations, we indicate that four twist⊥
3 multiparton distribution functions FLT , GLT , HLL, and HT T exist for tensor-polarized spin-1
hadrons. These multiparton distribution functions are also interesting to probe multiparton correlations in spin-1 hadrons.

Acceleration, Storage and Polarimetry of polarized Beams / 103

High Precision 5 MeV Mott Polarimeter
Authors: JOSEPH GRAMES1 ; C.K. Sinclair2 ; M. Poelker2 ; X. Roca-Maza3 ; M.L. Stutzman2 ; R. Suleiman2 ; Md. A.
Mamun2 ; M. McHugh4 ; D. Moser.2 ; J. Hansknecht2 ; B. Moffit2 ; T.J. Gay5
1

JEFFERSON LAB

2

Jefferson Lab

3

Department of Physics, Universita degli Studi di Milano, and INFN-Milan

4

George Washington University

5

University of Nebraska

Corresponding Author: grames@jlab.org

We report on the design and performance of a Mott polarimeter optimized for a nominal 5-MeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) injector. The rf time
structure of this beam allows the use of time of flight in the scattered electron detection, making it
possible to cleanly isolate those detected electrons that originate from the scattering foil, and resulting in measured scattering asymmetries which are exceptionally stable over a broad range of beam
conditions, beam currents, and foil thicknesses. In two separate series of measurements from two
different photocathode electron sources, we have measured the Mott scattering asymmetries produced by an approximately 86% transversely polarized electron beam incident on ten gold foils withnominal thicknesses between 50 and 1000 nm. The statistical uncertainty of the measured asymmetry from each foil is below 0.25%. Within this statistical precision, the measured asymmetry was
unaffected by ±1-mm shifts in the beam position on the target foil, and by beam current changes
and dead-time effects over a wide range of beam currents. The overall uncertainty of our beam polarization measurement, arising from the uncertainty in the value of the scattering asymmetry atzero foil thickness as determined from our fits to the measured asymmetries versus scattering foil
thicknesses, the estimated systematic effects, and the (dominant) uncertainty from the calculationof the theoretical Sherman function, is 0.61%. A simulation of the polarimeter using GEANT4 has
confirmed that double scattering in the target foil is the sole source of the dependence of the measured asymmetry on foil thickness, and gives a result for the asymmetry versus foil thickness in good
agreement with both our measurements and a simple calculation. Future measurements at different
beam energies and with target foils of different atomic numbers to bound uncertainties from small
effects such as radiative corrections to the calculation of the polarimeter analyzing power will also
be discussed.
“High precision 5 MeV Mott polarimeter”, J. M. Grames, C. K. Sinclair, M. Poelker, X. Roca-Maza, M.
L. Stutzman, R. Suleiman, Md. A. Mamun, M. McHugh, D. Moser, J. Hansknecht, B. Moffit, and T. J.
Gay, Phys. Rev. C 102, 015501 – Published 6 July 2020

Transverse Momentum Structure (TMD) / 104

Measurement of transverse single-spin asymmetries for dijet production in polarized p+p collisions at \sqrt{s} = 200 GeV at STAR
Author: Scott Wissink1

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1/ Book of Abstracts

Indiana University

Corresponding Author: wissink@indiana.edu

We report a new measurement of transverse single-spin
asymmetries for pair-production of jets in√collisions of transversely polarized protons at s = 200 GeV with data taken in 2012 and 2015 at⃗ of aSTAR. In this measurement we probe, at high Q2 , correlations between the transverse spin (S)proton, moving in the longitudinal (⃗p) direction, and the transverse momenta of partons (⃗kT ) within
the proton. A non-zero correlation – the Sivers effect – results in a spin-dependent shift in thedijet azimuthal opening angle away from 180◦ . The corresponding ⟨kT ⟩ is then calculated basedon a simple kinematic model. By using charge-tagging of the jets to enhance either u- or d-quark
contributions, we see a non-zero Sivers effect for the first time in dijet production in high-energy
proton collisions. The individual parton contributions (u, d, gluon+sea) to the measured ⟨kT ⟩ areextracted through a matrix inversion of the charge-sorted ⟨kT ⟩ data. Preliminary results and statusof the analysis will be presented.

Plenary Presentations / 105

Progress on fragmentation-function studies
Author: Felix Ringer1
1

LBNL

Corresponding Author: fmringer@lbl.gov

In recent years, significant progress has been made in improving our understanding of the QCD
fragmentation process. I will review theoretical and experimental advances that can shed new lighton both collinear and Transverse Momentum Dependent (TMD) fragmentation. Examples include
new extractions of fragmentation functions, hadron-in-jet fragmentation, and multi-differential measurements. In addition, I will review spin-polarized observables in electron-positron annihilation,
proton-proton collisions and at the future Electron-Ion Collider.

Transverse Momentum Structure (TMD) / 106

Transverse Single-Spin Asymmetries for π 0 and Electromagnetic
Jets at Forward Rapidities in p↑ +p Collisions at Center-of-Mass
Energies of 200 GeV and 500 GeV at STAR
Authors: Latiful Kabir1 ; zhanwen zhuNone
1

University of California at Riverside

Corresponding Author: latiful.kabir@ucr.edu

There have been numerous attempts, both experimentally and theoretically, to understand the origin of the unexpectedly large transverse single-spin asymmetries (AN ) for inclusive hadron production at forward rapidity in p↑ +p collisions that persist from low to high center-of-mass energies.
Two proposed potential sources are the twist-3 contributions in the collinear factorization and thetransverse-momentum-dependent contributions from either the initial-state quark and gluon Sivers
functions or the final-state Collins fragmentation function. To investigate the underlying physics
leading to this large AN , we study π 0 AN with different topologies – isolated and non-isolated, andAN for electromagnetic jets (EM-jets) of different substructures using Forward Meson Spectrometer(FMS) detector at STAR. Jet AN is sensitive to the initial state effect and can provide access to Sivers
functions. To investigate final-state effects, we measure the Collins asymmetry of π 0 inside EM-jets.
We present the most recent results for these asymmetries from p↑ +p collisions at 200 GeV and 500
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GeV. We also present new preliminary results of AN for EM-jets in FMS and Endcap Electromagnetic Calorimeter (EEMC) using p↑ +p collisions at 200 GeV where we explore the dependences of
AN on photon multiplicity inside the jet, jet transverse momentum, and jet energy. These results
provide rich information towards understanding the physics mechanism of large AN in hadron collisions.

Transverse Momentum Structure (TMD) / 107

General helicity formalism for two-hadron production in e+ e−
collisions and the Λ polarizing fragmentation function
Authors: Umberto D’Alesio1 ; Francesco Murgia2 ; Marco Zaccheddu1
1

University and INFN Cagliari

2

INFN Cagliari, Italy

Corresponding Author: umberto.dalesio@ca.infn.it

We present the complete structure of the azimuthal dependences and polarization observables for
two-hadron production in e+ e− annihilation processes within a TMD approach adopting the helicity formalism. The leading-twist quark and gluon TMD fragmentation functions (FFs) for spin-1/2
hadrons, with their properties and their probabilistic interpretation, are fully accounted for.
The role of the polarizing FF is discussed in detail and its extraction from Belle data for the transverse
polarization of Λ’s is shown. Predictions for SIDIS processes at EIC are presented.

Plenary Presentations / 108

Experimental studies on the high-energy spin physics in collider
experiments at RHIC
Author: Salvatore Fazio1
1

University of Calabria & INFN Cosenza - Italy

Corresponding Author: salvatore.fazio@unical.it

The Relativistic Heavy Ion Collider (RHIC) is the world’s only polarized proton+proton collider, capable of reaching center of mass energies up to 510 GeV. RHIC’s experiments, PHENIX and STAR,
have been carrying out a cold QCD program in order to gain deeper insight into the proton’s spin
structure and dynamics.
Data from longitudinally polarized p + p collisions allow one to study the gluon helicity distribution function (∆g(x)), by measuring the longitudinal double-spin asymmetry (ALL ) of pions andjets. On the other side, the transversely polarized proton collisions at RHIC enable the studies of thetransverse spin structure, such as the transversity and Sivers distributions, as well as polarized fragmentation functions. These studies can be used to test universality of transverse-momentum dependent distributions (TMDs) with respect to e+p processes, and constrain their evolution effects. Furthermore, unpolarized measurements of differential cross sections of weak bosons at RHIC provide
important constraints on the scale dependence of unpolarized TMDs in an x range (0.1 < x < 0.3)
that naturally complements the phase space accessed at the LHC.
In this talk, we present the recent measurements for longitudinal and transverse polarization, besides selected unpolarized results. PHENIX newly redesigned detector, sPHENIX is being installed
while STAR is currently installing a suite of new sub detectors in the forward region (2.5 < η < 4).
How those upgrades will supplement previous Spin measurements at RHIC will also be briefly discussed.
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Plenary Presentations / 109

Progress on Proton Charge Radius Measurements
Author: Ashot Gasparian1
1

North Carolina A&T State University

Corresponding Author: gasparan@jlab.org

Progress on Proton Charge Radius Measurements
Ashot Gasparian
NC A&T State University
for the PRad Collaboration
Abstract
The proton charge radius is one of the fundamental quantities in physics. For the past seventy years
it has been measured through elastic electron-proton scattering and ordinary hydrogen spectroscopy
methods. Over the years, results from both methods generally agreed with each other within theirexperimental uncertainties. Unexpectedly, in 2010 (and 2013) two experiments from newly developed muonic hydrogen atomic spectroscopy method reported results up to six standard deviations
smaller values than the accepted average from all previous experiments performed on ordinary hydrogen. This discrepancy triggered the well-known proton radius puzzle in hadronic physics. This
talk will discuss the post-2010 progress in proton radius measurement methods together with new experimental results and plans for new experiments. In particular, a novel magnetic-spectrometer-freeelectron-proton scattering experiment (PRad), performed at Jefferson Lab in 2016, will be presented
emphasizing its methods and results. Finally, the current status of the proton radius puzzle will bepresented and discussed.

Transverse Momentum Structure (TMD) / 110

Azimuthal asymmetry in J/ψ electroproduction as a probe to linearly polarized gluon distribution at electon-ion collider
Authors: Raj Kishore1 ; Asmita Mukherjee1 ; Mariyah Siddiqah1
1

IIT Bombay

Corresponding Author: 164120004@iitb.ac.in

We propose an estimate of cos(2ϕ) azimuthal asymmetry in J/ψ electroproduction, in an unpolarized
electron-proton scattering process. We have used a non-relativistic QCD (NRQCD) framework for
the J/ψ production rate. Within the kinematical range of the proposed Electron-Ion Collider (EIC),
this can investigate the linearly polarised gluon distribution in the unpolarized proton. We computethe azimuthal asymmetry in the kinematic region: z < 1, where the leading contribution comesfrom the photon-gluon fusion subprocess: γ ∗ g → QQ̄ + g. We use two alternative models for
TMDs to give the numerical estimate of the asymmetry: (1) the Gaussian-type parameterization and(2) the McLerran-Venugopalan model at small-x.

Polarized Sources and Targets / 111

Polarized H2 , D2 and HD molecules and their possible use to feeda polarized H2+ , D2+ or HD+ ion source for stripping injection intostorage rings
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Author: Ralf Engels1
Co-authors: Kirill Grigoryev 2 ; Ralf Gebel 3
1

Institute for Nuclear Physics, Research Center Juelich2Institut für Kernphysik, Forschungszentrum Jülich, Jülich, Germany

3Institut für Kernphysik, Forschungszentrum Jülich

Corresponding Author: r.w.engels@fz-juelich.deWith a dedicated apparatus it was shown that the nuclear polarization of hydrogen atoms and its
isotopes, produced by a polarized atomic beam source (ABS), can be preserved during the recombination into molecules. In this way, polarized H2 and D2 molecules in hyperfine substates where
both nucleons have equal spins are generated. In more recent experiments the ABS was used todetermine the spin of hydrogen and deuterium atoms passing through in parallel. In this case, thenuclear spins of the protons and the deuterons can be determined separately to get HD molecules
in any hyperfine substate, i.e. in any spin combination. One application of this technique can be
the design of an intense H2+ , D2+ or even an HD+ polarized ion source for stripping injection atstorage rings like COSY with polarization values above 0.8 and continuous intensities in the 10 μA
range.

Polarized Sources and Targets / 112

New aspects of storage-cell developments for the polarized internal target at LHCb
Author: Hendrik Smitmanns1
Co-authors: Kirill Grigoryev 2 ; Andreas Lehrach ; Ralf Engels 3
1

RWTH Aachen, FZ Juelich2Institut für Kernphysik, Forschungszentrum Jülich, Jülich, Germany

3Institute for Nuclear Physics, Research Center Juelich

Corresponding Author: hendrik.smitmanns@rwth-aachen.de

Like the ANKE experiment at COSY a polarized internal storage-cell target in front of the LHCb detector is the aim of the LHCSpin Projekt at CERN. This target will be an openable T-shaped tube thatwill be fed with a beam of polarized hydrogen atoms from an atomic beam source (ABS) operating
according to the Stern-Gerlach principle. One critical detail of such a storage cell is the surface coating that should minimize polarization losses due to wall collisions and recombination of the atoms
into less polarized molecules. Due to the restrictions of the LHC operations a carbon coating seems
to be the only option, but this has never been investigated for storage cells.
At the Institut für Kernphysik at Forschungszentrum Jülich, a setup is in use dedicated to study
polarization losses in storage cells as a function of surface materials, temperature, magnetic holding
fields or recombination processes. Therefore, this setup is a good tool to investigate carbon coatedstorage cells for further use at LHC.
Additionally, due to a slight modification of the ABS the influence of Lyman-α photons on the recombination process of hydrogen on the surface can be investigated.
In this talk, the setup of the storage cell investigations will be presented and the recombination process of hydrogen on a carbon surface will be discussed. The latter is also of interest for understanding
the formation of molecular hydrogen in interstellar clouds.

Nucleon Helicity Structure / 113
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Measurement of√Direct Photon Cross Section and Double Helicity
Asymmetry at s = 510 GeV in p⃗ + p⃗ Collisions at PHENIX
Author: Zhongling Ji1
1

Stony Brook University

Corresponding Author: zhongling.ji@stonybrook.edu

The proton spin decomposition provides key information about the structure of the nucleons. Sincelate 1980s, experiments showed that the quark spin contributes only ∼30\% to the proton spin, withremaining part coming from gluon spin as well as quark and gluon orbital angular momentum. Whilethe quark spin contribution was better constrained by polarized deep inelastic scattering (DIS), thegluon spin contribution remains less known, because it is probed through higher order processes(suppressed by ∼0.2 comparing to leading order processes) in DIS. The Relativistic Heavy Ion Collider (RHIC) is the only collider capable of producing two longitudinal polarized proton (⃗p +⃗p) beams.
Direct photon, jet and charged pion productions in p⃗ + p⃗ collisions can probe the gluon spin at leading order. Comparing with hadron productions, direct photon production is the most clean” channel,
since there is little fragmentation involved, and is considered thegolden” channel. However, the relatively small direct photon cross section compared to the hadron productions made it a challenging
observable, until the RHIC 2013 run, which provides the largest integrated luminosity (155 pb−1 ) inp⃗ + p⃗. In addition, the Electromagnetic Calorimeter at PHENIX has fine granularity to separate thetwo π 0 decay photons up to π 0 transverse momentum pT of 12 GeV/c, and a shower profile analysis
extends the γ/π 0 discrimination to beyond 20 GeV/c. These conditions finally made this “golden”
measurement come to reality. In this talk, I will present the isolated and inclusive direct photon
cross sections and their ratio for photon pT of 6–30 GeV/c, as well as the isolated direct photon
double helicity asymmetry (ALL ) for photon pT of 6–20 GeV/c. When included in global analyses
in the future, our results will provide an independent constraint on the gluon spin contribution to
the proton spin.

Joint TMD - GPD - HELCITY - Future session EU timezone / 114

Nucleon isovector tensor charge from lattice QCD with physicallight quark masses
Author: Ryutaro Tsuji1
Co-authors: Ken-Ichi Ishikawa 2 ; Yasumichi Aoki 3 ; Takeshi Yamazaki 4 ; Shoichi Sasaki 1 ; Yoshinobu Kuramashi

5

1

Tohoku University

2

Hiroshima University, Department of Physical Science3

KMI, Nagoya University

4

University of Tsukuba

5

Center for Computational Sciences, University of Tsukuba

Corresponding Author: tsuji@nucl.phys.tohoku.ac.jp

We will present the current status of nucleon structure studies with physical light quarks (mπ =135 MeV) in two large spatial extents of about 10 and 5 fm. Our calculations are performed on 2+1
flavor gauge configurations generated by PACS collaboration with the stout-smeared O(a) improved
Wilson fermions and Iwasaki gauge action at β=1.82 corresponding to the lattice spacing of about
0.08 fm. In this talk, we mainly focus on nucleon isovector couplings of axial vector, scalar andtensor channels. Especially, the tensor coupling is known as the 1st Mellin moment of transversely
parton distribution function and is itself related to the information of the quark-EDM.

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Transverse Momentum Structure (TMD) / 115

First global extraction of the worm-gear TMD g1T
Authors: Shohini Bhattacharya1 ; Zhongbo KangNone ; Andreas Metz1 ; Gregory Penn2 ; Daniel PitonyakNone
1

Temple University

2

Yale University

Corresponding Author: tug23108@temple.edu

In this talk, we report on the first simultaneous extraction of the worm-gear function g1T , one of theeight leading-twist TMDs. The study analyzes HERMES, COMPASS and JLab semi-inclusive deepinelastic scattering data using Monte Carlo techniques. We provide a comparison of g1T obtained
from this experimental data with lattice QCD calculations, a large Nc analysis, and the WandzuraWilczek-type approximation.

Joint TMD - GPD - HELCITY - Future session US timezone / 116

Role played by the zero modes in the matching for the twist-3
PDFs
Authors: Shohini Bhattacharya1 ; Krzysztof Cichy2 ; Martha Constantinou1 ; Andreas Metz1 ; Aurora Scapellato1 ;Fernanda Steffens3
1

Temple University

2

Adam Mickiewicz University

3

Bonn University

Corresponding Author: tug23108@temple.edu

The quasi-PDF approach has made it possible to extract the light-cone PDFs from lattice QCD. In
this approach, one calculates matrix elements of space-like operators for boosted hadrons. QuasiPDFs can be related to the light-cone PDFs through a perturbatively calculable matching coefficient.
We address the matching for the very first time for the twist-3 PDFs gT (x) and hL (x). In this talk,
we focus on potential complications in the matching due to the presence of singular zero-mode
contributions.

Joint TMD - GPD - HELCITY - Future session US timezone / 117

Lattice results on twist-3 parton distributions
Authors: Shohini Bhattacharya1 ; Krzysztof Cichy2 ; Martha Constantinou1 ; Jack Dodson1 ; Andreas Metz1 ; Aurora
Scapellato1 ; Fernanda Steffens3
1

Temple University

2

Adam Mickiewicz University

3

Bonn University

Corresponding Author: aurora.scapellato@temple.edu

Twist-3 distributions are very important quantities for the study of hadron structure, and presently
they are poorly known experimentally. In this talk, we present the first-ever results on the proton
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iso-vector twist-3 PDFs gT (x) and hL (x), obtained from lattice QCD. We employ the quasi-PDF approach, which is based on computation of correlation functions between two boosted proton states
at finite momentum, that are eventually matched to the light-cone distributions through perturbative matching formulae, that we developed specifically for twist-3 PDFs.
Our calculations are performed on a gauge ensemble with two degenerate light quarks, a strange
and a charm quark (Nf = 2 + 1 + 1), with lattice spacing a = 0.093 fm and pion mass Mπ = 270
MeV.
The proton is boosted to 0.83 GeV, 1.25 GeV and 1.67 GeV to check momentum convergence. On thesame ensemble we also extract the twist-2 counterparts and test the Wandzura-Wilczek approximation.
Extending the methodologies developed for PDFs, we also present preliminary results for twist-3
GPDs.

Future facilities and experiments / 118

Single-spin asymmetry measurements in inclusive production of
K⁰s and ω (782) mesons at U70 (Protvino).
Authors: Konstantin Novikov1 ; N.K. Kalugin2 ; V.V. Mochalov2 ; V.V. Moiseev 2 ; M.B. Nurusheva3 ; V.L. Rykov 3 ; P.A.
Semenov2 ; A.N. Vasiliev2
1

Institute for High Energy Physics (IHEP) - ISTC

2

NRC “Kurchatov Institute” – IHEP, Protvino

3

NRNU MEPhI, Moscow

Corresponding Author: knovikov@ihep.ru

The SPASCHARM project is aimed at studying a fundamental problem of modern particle physics,
such as the mechanism of spin asymmetries in the production of hadrons. The goal of the first stageof the SPASCHARM experiment at the U-70 accelerator in Protvino is the study of single-spin asymmetry in different reactions using negative pion beam with a polarized proton target. SPASCHARM
setup was commissioned and will start data taking this fall. Second stage of the SPASCHARM experiment will measure spin effects using polarized proton and antiproton beams.
The specific task of this talk is to study possibility to measure single-spin asymmetry in inclusive
production of K⁰s and ω (782) mesons at negative pion and polarized antiproton beams. The measurement of inclusive production of K⁰s and ω (782) mesons with polarized antiproton beam areplanning for the first time. Expected statistic accuracies of single-spin asymmetry in inclusive production of K⁰s and ω (782) mesons are presented. The expected accuracy is 1-2% in different kinematic
regions.

Spin in Nuclear Reactions and Nuclei / 119

POLARIZATION TEST FOR QUASI-FREE KNOCKOUT OF NUCLEON
FROM NUCLEAR SHORT-RANGE CORRELATED NN PAIR
Author: Yuriy Uzikov1
1

Joint Institute for Nuclear Researches, DLNP

Corresponding Author: uzikov@jinr.ru

Short-range correlated (SRC) NN pairs play an important role in structure of atomic nuclei andare actively studied using electron and proton beams [1]. Recently the reaction 12 C+p 10 A+pp+N
was studied at BM@N in JINR [2] using the 12 C beam at energy of 4 GeV/nucleon interacting withthe hydrogen target to probe the SRC pairs {pN} in the 12 C. The pp scattering in the subprocess
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p+{pN} p+p+N occured at the scattering angles ~ 90° in the pp c.m.s. and all three final nucleons
were detected as well as the residual nucleus 10 A. For theoretical analysis of this reaction [3] is useda properly modified approach developed earlier [4] to describe the quasi-elastic knock-out of fast
deuterons from the light nuclei 12 C and 7,6 Li by protons in the reactions (p,pd) and (p,nd). A basic
assumption in theoretical description of SRC NN correlations in nuclei is a factorization of the twonucleon momentum distribution in nucleus n(k1 , k2 ) over the internal, nrel (qrel ), and the c.m.s.,ncm (kc.m. ), momenta [1]. For the internal nrel (qrel ) distribution the deuteron (or singlet deuteron)wave function squared is used for the realistic NN-interaction potentials. Relativistic effects in thequasi-elastic knockout of nucleon from the SRC pair p+{NN} p+N+N are taken into account in thelight-front dynamics [5] similarly to the deuteron breakup reaction p+d p+p+n. According to theresults of the data analysis of the 12 C+p 10 A+ pp+N reaction [2] the initial and final state interaction(ISI&FSI) with nuclear medium is nonimportant in the reaction in question at kinematic conditionsof the BM@N experiment. Here we estimated the ISI&FSI effects within the eikonal approximation
using the Glauber model for the N-10 A scattering. The one-loop approximation with elastic N-10 A
rescatterings was applied and the ISI&FSI effect was found to be moderate. However, another question concerning the mechanism of the subprocess p+{NN} p+N+N and the role of ISI&FSI in it ismuch less clear. Only in case of dominance of the quasi-free mechanism (or impulse approximation)of the nucleon knockout in the subprocess p+{NN} p+N+N one can extract the internal momentum
distribution nrel (qrel ) from the data on the reaction 12 C+p 10 A+ pp+N. One can show (see Ref. [6]and references therein), that the tensor analyzing power T20 of the reaction p+d p+p+n for the quasifree mechanism of the nucleon is easily expressed via the ratio u(q)/w(q) of the S- and D- componentsof the deuteron wave function in the momentum space u(q) and w(q), respectively, and has a very
specific behavior as a function of the module of q [6]. Therefore, a measurement of the T20 in thereaction p+d p+p+n at the same kinematics as for the subprocess p+{NN} p+N+N in the reaction
A(p,ppN)B, i. e. at large momentum of the nucleon spectator and large pp-scattering angle ~ 90°, anda subsequent comparison with the results of the IA calculation of the T20 , will provide a crucial test
for the quasi-free mechanism of this subprocess. A similar test based on the measurement of the T20of the reaction e+d e+p+n can be used to check quasi-free mechanism of the nucleon knockout byelectron from the SRC NN pair in the reaction A(e,epN)B.
This work is supported in part by the RFBR grant № 18-02-40046.
1. O. Hen et al., Rev. Mod. Phys. 89 (2017) 045002.
2. M. Patsyuk et al. Nature Phys. 17 (2021) 693; arXiv:2102.02626 [nucl-ex].
3. Yu.N. Uzikov, Izv. RAN, Ser. Fiz. 84 (2020) 580.
4. M.A. Zhusupov, Yu.N. Uzikov, Fiz. El. Chast. At. Yadr. 18 (1987) 323.
5. Yu.N. Uzikov, EPJ Web Conf, 222 (2019) 03027.
6. S.L. Belostotski et al., Phys. Rev. C 56 (1997) 50.

Polarized Sources and Targets / 120

NMR With Machine Learning
Authors: Devin Seay1 ; Ishara Fernando1 ; Dustin Keller1
1

University of Virginia

Corresponding Author: das5pzq@virginia.edu

Constant current continuous wave Nuclear Magnetic Resonance (NMR) has been an essential tool forpolarized target experiments in Nuclear and High-energy physics. Q-meter based phase-sensitive
detection can provide accurate monitoring of the polarization over the course of a scattering experiment with limitations due to some operational parameters. In this talk, we present recent studiesof improved signal to noise in polarization measurements as well as reliable measurements outsideof the designated range of the Q-meter’s operational parameters with the use of machine learning(ML).

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Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 122

Weinberg operator contribution to the hadronic CP violation
Author: Nodoka Yamanaka1
1

KMI, Nagoya University

Corresponding Author: nodoka.yamanaka@riken.jp

The Weinberg operator (chromo-electric dipole moment of gluon) is a CP violating quantity generated in many candidates of new physics beyond the standard model, and it contributes to observables
such as the electric dipole moments (EDM) of the neutron, nuclei and atoms.
In this presentation, we review the present understanding of the Weinberg operator.

Future facilities and experiments / 123

AI in Spin Physics and the future of spin at Fermilab
Author: dustin keller1
1

University of Virginia

Corresponding Author: dustin@virginia.edu

The use of the Fermilab main injector proton beam with an energy of 120 GeV and a 4.4-second
spill every minute in combination with a polarized target provides a unique opportunity for future spin physics experiments. New technology in RF manipulated dynamically polarized (DNP)
target systems rely on artificial intelligence to optimally configuration the target polarization stateusing the signal from continuous wave nuclear magnetic renounce (NMR). The target spins can beautonomously oriented in the time between spills allowing for the access of novel observables. Machine learning tools are advancing instrumentation potential as well as information extraction in
Spin Physics. Some examples are provided, with a focus on possible future experiments at Fermilab.

Polarized Sources and Targets / 125

SpinQuest Polarized Target: An Overview
Authors: Ishara Fernando1 ; Dustin Keller1 ; Zulkaida Akbar1 ; Anchit Arora1
1

University of Virginia

Corresponding Author: cee9hc@virginia.edu

The SpinQuest experiment at Fermilab aims to extract Sivers functions for the sea quarks in the rangeof 0.1 < xB < 0.5 through single spin asymmetry measurements of di-muon pairs resulting from theDrell-Yan process. The proposed beam intensity is 1.5 × 1012 of 120 GeV unpolarized proton/sec. The
experiment utilizes a transversely polarized fixed target system which consist of a 5T superconducting magnet, NH3 and ND3 targets, a 4He evaporation refrigerator, a 140 GHz microwave source anda large pumping system. The expected average target polarization is 80% for protons, and 32% for
deuterons. The polarization will be measured using Q-meter based NMR system. An overview of thepolarized target system, including polarization measurements will be presented in this talk.

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Transverse Momentum Structure (TMD) / 126

SU(3)-flavor TMD PDFs extraction with global fits & ANN
Authors: Ishara Fernando1 ; Dustin Keller1 ; Devin Seay1 ; Nicholas Newton1 ; dustin keller1
1

University of Virginia

Corresponding Author: cee9hc@virginia.edu

Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs) can be extracted fromthe processes that are corresponding to multiple kinematic scales such as Drell-Yan (DY), Semi Inclusive Deep Inelastic Scattering (SIDIS) and e+ e− annihilation. Among the eight leading- twist
TMD PDFs, there are two time-reversal odd TMDs, namely Sivers function & Boer-Mulders function, which represent the correlation between the spin of the quark and the spin of the hadron.
These T-odd TMD PDFs have conections to the partons’ orbital angular momenta contributing tothe overall angular momentum of the hadron. Not only implementing global fits to the available
data, but also an Artificial Neural Network (ANN) can be trained with regression to simulate thesetime-reversal odd TMDs. A preliminary analysis in the case of SU (3)f lavor TMDs extraction using
an ANN with available experimental data will be presented in this talk.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 127

Muon g-2/EDM Experiment at J-PARC
Author: Yusuke Takeuchi1
Co-author: J-PARC muon g-2/EDM Collaboration
1

Kyushu University

Corresponding Author: takeuchi@epp.phys.kyushu-u.ac.jp

In the anomalous magnetic moment of muons (muon g−2), there was a discrepancy of more than 3σ
between the Standard Model prediction and the experimental value measured with an accuracy of
0.54 ppm by Brookhaven National Laboratory (BNL) E821 experiment, and it has long been argued
that this might be a sign of new physics beyond the Standard Model. Recently, Fermilab’s experimental group improved BNL’s experimental equipment and conducted experiments in a similar method.
The result is consistent with the previous experiment, and the discrepancy between the average ofthe two experiments and the Standard Model prediction was updated to 4.2σ. As a result, expectations for new physics discoveries are rising even more. However, since the two experiments employ
the same method, it is extremely important to measure with different new methods and confirm thediscrepancy. To validate the discrepancy, an experiment with a completely independent approachfrom the previous two experiments is planned at Japan Proton Accelerator Complex (J-PARC). The
J-PARC experiment aims to measure the muon g−2 with a precision of 0.1 ppm and search for muon
electric dipole moment with a sensitivity of 1.5×10−21 e·cm. The overall design of the experimentand its preparation status will be presented.

Plenary Presentations / 128

T-violation in neutron scattering
Authors: Masaaki Kitaguchi1 ; NOPTREX collaboraionNone
1

Nagoya University

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Corresponding Author: kitaguchi@phi.phys.nagoya-u.ac.jp

The fundamental symmetry violation can be studied by using nuclear reactions with polarized neutrons beam and target nuclei. The large enhancement of the parity violation was observed in theneutron capture reactions for some nuclei. It is predicted that time reversal symmetry violation is
also enhanced with the same mechanism. Our recent results of 139La(n, γ) reaction suggested thatthe enhancement is large enough to search T-violation with high sensitivity, which can be reachto the sensitivity of neutron electric dipole moment and which has different systematics. We are
performing the research and development for the T-violation search experiment at J-PARC, for example, details of nuclear reactions with candidate nuclei and that of experimental setup. We are also
developing the polarization technique for both of neutron beam and target nuclei, so-called spin
exchange optical pumping and dynamic nuclear polarization, respectively.

Spin in Nuclear Reactions and Nuclei / 129

Development of a polarized proton target for spin-correlation coefficient measurements
Author: Atomu Watanabe1
Co-authors: Kenichiro Tateishi 2 ; Kimiko Sekiguchi 1 ; Tomohiro Uesaka 3 ; Yuko Saito 1
1

Tohoku University

2

RIKEN

3

RIKEN Nishina Center

Corresponding Author: watanabe@lambda.phys.tohoku.ac.jp

The study of three-nucleon forces (3NFs) is essential for clarifying various nuclear phenomena. The
3NFs arise naturally in the meson exchange model as well as in the framework of chiral effective
field theory (EFT). With the aim of pinning down the 3NF effects in comparison with the rigorous numerical calculation based on the chiral EFT, we plan to measure the complete set of spin-correlation
coefficients for deuteron-proton elastic scattering at intermediate energies (∼ 100 MeV/nucleon).
For the measurement of spin-correlation coefficients, we develop the polarized proton target.
We require the following conditions for the polarized proton target system: 1) covering a wide angular range in the horizontal and vertical scattering plane, 2) high polarization (> 20%), and 3) a
low magnetic field (∼ 0.1 T). We adopt a dynamic nuclear polarization (DNP) with photo-excitedtriplet electron spins (so-called triplet DNP method) to produce polarized protons. The polarizedtarget is a single crystal of naphthalene doped with pentacene and has a size of ϕ10 × 3 mm3 . In
this conference, we report the newly developed polarized proton target system.

Plenary Presentations / 130

Measurement of muon g-2
Author: Vladimir Tishchenko1
1

Brookhaven National Laboratory

Corresponding Author: vtishchenko@bnl.gov

At present, there is a discrepancy between the Standard Model calculation and the measured valueof the anomalous magnetic moment of the muon aµ . This disagreement may arise from new physics,
or from an omission in either theory or experiment. Ongoing international efforts on both fronts
aim to resolve the source of this discrepancy. This talk will present the progress and prospects ofprecision measurements of aµ .
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Acceleration, Storage and Polarimetry of polarized Beams / 131

HIGH VOLTAGE DESIGN AND EVALUATION OF WIEN FILTERSFOR THE CEBAF 200 keV INJECTOR UPGRADE
Authors: Gabriel Palacios Serrano1 ; Carlos Hernández García1
1

Thomas Jefferson National Accelerator Facility

Corresponding Authors: gabrielp@jlab.org, chgarcia@jlab.org

Our contribution describes design, fabrication and testing of the high voltage system to upgrade the
Wien spin rotator to be compatible with the 200 keV electron beam. This required Solidworks modeling, CST and Opera electro- and magnetostatic simulations, upgrading HV vacuum feedthroughs,
and assembly techniques for improving electrode alignment. The electric and magnetic fields required by the Wien condition and the successful HV characterization under vacuum conditions arealso presented.

Acceleration, Storage and Polarimetry of polarized Beams / 132

New Spin Tracking Software Developed For General Particle Tracer
Authors: Mark Stefani1 ; S.B. van der Geer2
1

JLab

2

Pulsar Physics

Corresponding Author: mstefani@jlab.org

A new particle spin tracking feature has been developed and implemented within General Particle
Tracer (GPT). Simulating polarized particles under various conditions within accelerators requires
the classical dynamics and time-dependent spin equation of motion. These equations capture theparticles behavior as it interacts with electro-magnetic fields. The GPT-Spin extension is able to track
particle spin coordinates in GPT using the generalized Thomas-BMT equation. GPT is based on fully
relativistic 3D particle-tracking techniques, providing a solid basis for the study of all 3D and nonlinear effects of charged-particles dynamics, now including spin, in electro-magnetic fields. New or
modified GPT elements have been implemented to initialize and simulate an arbitrary particle beamwith spin. Built in or custom elements and field maps can all be used to perform highly specialized
calculations for specific applications. This work will present benchmark simulations and details of
the newly available GPT -Spin feature.

Transverse Momentum Structure (TMD) / 133

Transverse Single Spin Asymmetry of Forward Neutrons at PHENIX
Author: Mriganka Mouli Mondal1
1

CFNS, Stony Brook University

Corresponding Author: mrigankamouli.mondal@stonybrook.edu

Very forward neutron production cross sections in proton proton collisions are well described by a
one pion exchange (OPE) mechanism. However, the simple OPE model alone was not able to explain
the large transverse single spin asymmetry (AN ) that was discovered at RHIC in polarized proton
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proton collisions. An interference between the spin-flip pion exchange and non-flip a1 -Reggeon
exchange could create asymmetries, and such a model reasonably describes the measurements.
More interestingly, recent PHENIX measurements in p+A collisions at 200 GeV show surprisingly
strong nuclear dependence of AN , resulting from the interplay of different neutron production mechanisms. To understand the mechanisms in detail explicit transverse momentum pT and longitudinal
momentum fraction xF dependent analyses are performed. In addition, correlation analysis withother detector activity provides additional information on how different interactions contribute to
the asymmetry.
For a large phase space coverage in xF and pT it is also essential to make the measurements overa wide range of √center of mass energy of collisions. PHENIX has taken polarized proton proton
collision data at s = 62, 200, 500 and 510 GeV.
At PHENIX the Zero degree calorimeter (ZDC) is used for neutron detection in conjunction with
the Beam Beam Counter (BBC) for tagging√ various event topologies. We will show results for explicit pT and xF dependence of AN at s = 200 GeV in p ↑ +p, p ↑ +Al and p ↑ +Au collisions.
We will also show the current status of the center of mass energy dependence analysis for p ↑ +p
collisions.

Transverse Momentum Structure (TMD) / 134

Sivers azimuthal asymmetry in inelastic J/ψ leptoproduction
Authors: Francesco Murgia1 ; Umberto D’Alesio2 ; Asmita Mukherjee3 ; Sangem RajeshNone ; Cristian PisanoNone

1

INFN Cagliari, Italy

2

University and INFN Cagliari

3

IIT Bombay

Corresponding Author: francesco.murgia@ca.infn.it

We study the Sivers azimuthal asymmetry for J/ψ production in semi-inclusive deeply inelastic scattering, with the aim of gaining information on the poorly known gluon Sivers function. We concentrate on the J/ψ low transverse momentum region, adopting the transverse-momentum dependent
generalized parton model (GPM), and its color gauge invariant extension (CGI-GPM), which includes
final state interactions at leading order. We consider the nonrelativistic QCD (NRQCD) scheme forthe quarkonium formation mechanism. We compare our results for unpolarized cross sections andthe Sivers asymmetry with available data, respectively from HERA and COMPASS, giving estimates
for the asymmetry in the kinematical regime of the future Electron-Ion Collider (EIC).

Joint BSM - Accelerator - Future Session EU timezone / 135

Polarization facilities at the JINR accelerator complex
Author: Victor Fimushkin1
Co-authors: Aleksander Belov 2 ; Roman Kuzyakin 1 ; Mikhail Kulikov 1 ; Ludmila Kutuzova 1 ; Yuri Prokofichev 1 ;Aleksey Shumkov 1
1

Joint Institute for Nuclear Research

2

Institute for Nuclear Research of RAS

Corresponding Author: fimushkin@jinr.ru

Polarization facilities are being developed at the JINR accelerator complex in the framework of thepolarization research program under the NICA project. Those are the polarized deuteron and protonsource SPI, SPI low energy and linac output polarimeters, and the absolute polarimeter at the NICA
collider. The status of the above facilities and the results achieved are presented.
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Future facilities and experiments / 136

Machine Learning Online Monitoring for the SpinQuest experiment at Fermilab
Author: Arthur Conover1
1

University of Virginia

Corresponding Author: acc5dn@virginia.edu

The SpinQuest experiment (E1039) is a transversely polarized fixed target experiment at Fermi National Accelerator Laboratory designed to measure the sea-quark Sivers functions via the Drell-Yan
process. An unpolarized beam of 120-GeV protons will interact with a transversely polarized proton
or deuteron target which will produce Drell-Yan dimuon events. Those muons will be detected in
the spectrometer which allows for the extraction of the single-spin transverse asymmetry. Fast online monitoring is necessary to scan the quality of the incoming data and the general health of theexperiment. Machine learning techniques can be used to speed the reconstruction of dimuon eventsand monitor any false asymmetry measured in each spill. Additionally, slow controls information
can be integrated, allowing for automation of diagnostics and quality checks during the experiment,
potentially reducing the overall systematic error of the experiment.

Polarized Sources and Targets / 137

Dynamical Behavior of the SpinQuest Target Polarization due to
Beam Heating and Radiation Damage
Authors: Zulkaida Akbar1 ; Shyh-Tse Linus Chiou1 ; Dustin Keller1
1

University of Virginia

Corresponding Author: za2hd@virginia.edu

The SpinQuest experiment at Fermilab will utilizes a high intensity 120 GeV proton beam incident
on a transversely polarized target. The likely behavior of the SpinQuest polarized target due to beam
heating and radiation damage has been recently analyzed. The target temperature will increase dueto the beam heating which can cause local depolarization of the target material. The temperature of
the target also depends on heat removal by the helium evaporation refrigerator. A simulation basedon the finite-difference method was applied to obtain the final temperature of the target under the
SpinQuest configuration. The radiation level in the target material was studied using GEANT toobtain the intensity of secondary particle production along the target length. Finally, using thetarget temperature and beam irradiation information, a LabView-based simulation was developed to
calculate the depolarization in the target material as a function of position along the target length. In
this talk, I will present the degree of dynamic target depolarization and the information and approach
intended for reducing the systematics for these effects.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 138

Search for permanent EDM using Fr atoms
Author: Motoki Sato1
Co-authors: Yasuhiro Sakemi 2 ; Hiroki Nagahama 3 ; Keisuke Nakamura 3 ; Naoya Ozawa 4 ; Shintaro Nagahse 5 ;Mirai Fukase 5 ; Daisuke Uehara 5 ; Keita Kamakura 6 ; Yasuyuki Matsuda 7 ; Kazeki Yamane 7 ; Teruhito Nakashita
7; Takatoshi Aoki 7 ; Kazuo Tanaka 8 ; hideki ueno 9 ; Aiko Takamine 9 ; Hiromitsu Haba 10 ; Tomohiro Hayamizu 11 ;Yuichi Ichikawa 12 ; Yukari Matsuo

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1

University of Tokyo

2

CNS, the university of Tokyo

3

CNS, The University of Tokyo

4

CNS, University of Tokyo

5

CNS. The univ. of Tokyo

6

CNS, The univ. of Tokyo7

The univ. of Tokyo, Komaba

8

CYRIC, Tohoku univ

9

RNC

/ Book of Abstracts

10

Nishina Center for Accelerator-Based Science, RIKEN

11

RIKEN

12

Kyushu University

Corresponding Author: msato@radphys4.c.u-tokyo.ac.jp

The existence of the permanent Electric Dipole Moment (EDM) implies the time reversal symmetry
violation. This violation directly means CP violation by the CPT theorem, and it would be expected
to explain the observed matter-antimatter asymmetry. The electron EDM, which is the possible
signal of the T-violation predicted by the Standard Model (SM) is too small to be measured withcurrent experimental technique and the larger EDM would indicate a new physics beyond SM. Thistiny EDM for the electron can be enhanced by the relativistic effects in the heavy atoms such as
francium (Fr).
In this report, we will see the overview of the experiment of the search for EDM using two isotopesof Fr developed at RIKEN. One is 210-Fr, produced by a nuclear fusion-evaporation reaction between
gold target and oxygen beam supplied from AVF cyclotron, and the other is 221-Fr, produced fromthe alpha decay of 225-Ac, which can be used as the generator for 221-Fr, and has a long lifetime ~10 days. Both isotopes have large enhancement factor of 895 compared with electron EDM, which
can be calculated very precisely with the relativistic coupled cluster theory. The 221-Fr nucleus has,on the other hand, a large octupole deformation effect and can become the candidate to search forthe nuclear EDM.
We conducted the high intensity surface ionizer to produce the Fr ions, the neutralizer which is used
to recombine the electron to the Fr ion, and the Magneto-optical trap (MOT) for the Fr cooling andtrapping. All the experimental apparatus were successfully developed and operated, and also thedevelopment of the new experimental apparatus to produce the high intensity 225-Ac source, andlaser cooling for 221-Fr is now in pogress. The present status and expected sensitivity for the EDM
with the trapped cold Fr atoms will be discussed.

Transverse Momentum Structure (TMD) / 139

Probing gluon TMDs via open heavy flavor quark production at
the EIC
Authors: Dingyu Shao1 ; Zhong-Bo Kang2 ; Kyle Lee3
1

Fudan University

2

University of California, Los Angeles

3

Lawrence Berkeley National Laboratory

Corresponding Author: dingyu.shao@cern.ch

In this talk, I will introduce our recent study on the probing transverse momentum-dependent gluon
Sivers function in open heavy flavor quark production at the future EIC. We derive the theoretical framework to calculate heavy-quark pair production in the small transverse momentum region.
Based on the factorization and resummation formula, we resum large logarithms in the small qT
region and present the theoretical predictions for the single-spin asymmetry.
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Future facilities and experiments / 140

Online Reconstruction on GPUs for J/ψ TSSA Study at SpinQuest
Author: Catherine Ayuso1
1Mississippi State University

Corresponding Author: cayuso@umich.edu

E1039/SpinQuest is a fixed target experiment at Fermi National Accelerator Laboratory that uses atransversely-polarized target to explore the sea quark and gluon Sivers functions via the measurement of the transverse single spin asymmetry (TSSA) for a number of physics processes includingJ/ψ, ψ’ and Drell-Yan production. The experiment employs a 120-GeV extracted proton beam colliding with transversely-polarized NH3 and ND3 cryogenic targets. The SpinQuest spectrometer is
optimized to detect the oppositely-charged muon pair produced in these processes. In pursuit ofthese asymmetry measurements, we are developing an advanced graphical processing unit (GPU)based multi-threaded framework that allows for an efficient parallelization of the online data processing flow and track reconstruction along with diagnostics and visualization tools. In this talk,I will report the progress of the ptimization of the offline track reconstruction in GPU by this autumn to reach real-time data visualization and monitoring. I will also present results estimating the
anticipated precision of TSSA measurement via J/ψ production from the first SpinQuest production
data.

Joint GPD - Helicity session / 141

Novel CFFs Extraction in Unpolarized DVCS
Authors: Liliet Calero Diaz1 ; Dustin Keller2 ; Zulkaida Akbar2
1

UVA

2

University of Virginia

Over the last 20 years there has been intense experimental activity dedicated to the measurement ofobservables to help build a 3D description of the nucleon. Generalized parton distributions (GPDs)
describe complementary aspects of the structure of hadrons, providing qualitative and quantitative
information about the partonic structure and dynamics such as orbital angular momentum. The
formulation of the DVCS cross section is parametrized in terms of Compton Form Factors (CFFs)
which are convolutions of GPDs with coefficient functions computed from perturbative QCD.This
talk presents the most recent DVCS helicity amplitude formulations aimed at extracting CFFs andexplores their distinctive kinematic characteristics.

Nucleon Helicity Structure / 142

Recent Longitudinal Spin Results with Charged Pions and Jets at
PHENIX
Author: Ross Corliss1
1

Stony Brook University

Corresponding Author: ross.corliss@stonybrook.edu

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Operated at the Relativistic Heavy Ion Collider at Brookhaven until beginning its recent upgrade
into sPHENIX, the PHENIX experiment has collected a wealth of data from polarized proton collisions. Analysis of these data sets continues to offer insight into the spin structure of the proton. In
particular, RHIC’s polarized proton-proton data help constrain polarized PDFs in the proton, and the
double spin asymmetry of various processes is sensitive to gluons at leading order. I will give a brief
overview of the detector and recent results in charged pion and jet asymmetries, as well as a discussion of the impact these measurements have on our understanding of parton polarizations.

Transverse Momentum Structure (TMD) / 143

Transverse Single Spin Asymmetries of Midrapidity Heavy Flavor Electrons and Charged Pions in 200 GeV p↑ + p Collisions at
PHENIX
Author: Dillon Fitzgerald1
1

University of Michigan, Ann Arbor

Corresponding Author: dillfitz@umich.edu

Understanding the transverse spin and momentum structure of the proton is of large interest to
the nuclear physics community and it is one of the main goals of the spin physics program at theRelativistic Heavy Ion Collider (RHIC). Transverse single spin asymmetry measurements for particles produced in proton-proton collisions provide insight into initial and final state spin-momentum
and spin-spin parton-hadron correlations. In particular, electrons from heavy flavor decays provide
access to initial state spin-momentum correlations of gluons in the proton, while charged pions provide access to both initial and final state transverse spin effects of quarks and gluons. Electrons andcharged pions are measured at midrapidity at PHENIX using the central arm spectrometers which
consist of an electromagnetic calorimeter, a ring-imaging Cherenkov detector, as well as drift andpad chambers. In addition, the heavy flavor decay electron analysis uses the silicon vertex detector
in order to veto background from conversion electrons. Recent results from both the electron andcharged pion measurements from the 2015 running period (200 GeV p↑ +p) will be presented.

Plenary Presentations / 144

Nuclear spin-isospin responses studied by nuclear reactions: A
tribute to Munetake Ichimura
Author: Tomotsugu Wakasa1
1

Kyushu University

Corresponding Author: wakasa@phys.kyushu-u.ac.jp

Progress in the nuclear spin physics studied by nuclear reactions is briefly reviewed with particularemphasis on the contributions of Munetake Ichimura and his research-group.
Much of his recent work was based on a comprehensive framework consisting of a distorted wave
impulse approximation (DWIA) with response function calculated by a continuum random phaseapproximation(RPA).
We pay special attention to two contrasting problem.
One is the quenching of the total Gamow-Teller (GT) transition strength with respect to the modelindependent GT sum rule (Ikeda’s sum rule).
The other is the enhancement of the pionic modes at relative large momentum transfers as a precursor phenomenon of pion condensation.
A main aim of this review is to gain an overall understanding of the behavior of these spin-isospin
modes.
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Furthermore, recent developments in the isospin dependence of the spin-isospin residual interaction
studied by the GT resonances for unstable nuclei as well as the tensor correlation effects observedin the spin-dipole resonances are also addressed.

Transverse Momentum Structure (TMD) / 145

Geometric model for Drell-Yan processes and TMDs
Authors: Oleg TeryaevNone ; Jen-Chieh Peng1 ; Wen-Chen Chang2 ; Randal Evan McClellan3
1

University of Illinois

2

Institute of Physics, Academia Sinica

3

Pensacola State College

Corresponding Authors: changwc@phys.sinica.edu.tw, jcpeng@illinois.edu, remcclellan@pensacolastate.edu,
teryaev@jinr.ru

The tensor polarization of virtual photons revealed in angular distributions of Drell-Yan processes
may be described in simple geometric model.
The results are compared with collier and fixed target data. The model compatibility with pQCD is
discussed.
The contribution as a background for TMDs (in particular, Boer-Muders distribution) studies is considered

Form Factors and GPDs / 146

Time-like gravitational formfactors and shear viscosity
Author: Oleg TeryaevNone
Corresponding Author: teryaev@jinr.ru

The extraction of time-like gravitational formfactors from exclusive meson pair production is discussed. The special attention is payed to structures which should cancel between quarks and gluons
but may be non-zero for quarks. In particular, dipole term may be associated with shear viscosity.
Its studies in exotic hybrid mesons production is addressed. The smallness of the respective GDA
may be an analog of smallness of shear viscosity in holographic approach,Spin in Nuclear Reactions and Nuclei / 147

Proton-3He elastic scattering at intermediate energies
Authors: Kimiko Sekiguchi1 ; Atomu Watanabe1 ; Shin’nosuke Nakai1 ; Yasunori Wada1 ; Kenjiro Miki1 ; Takashi Ino2 ;Kichiji Hatanaka3 ; Hiroki Kanda4 ; Nobuyuki Kobayashi4 ; Yukie Maeda5 ; Hooi Jin Ong4 ; Hideyuki Sakai6 ; Atsushi
Tamii7 ; D. T. Tran4 ; Tomotsugu Wakasa8 ; Takashi WakuiNone ; Masatoshi Itoh91

Tohoku University

2

KEK

3

RCNP

4

RCNP, Osaka University

5

University of Miyazaki

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6

RNC

7

Research Center for Nuclear Physics

8

Kyushu University

9

CYRIC, Tohoku University/ Book of Abstracts

Corresponding Author: kimiko@lambda.phys.tohoku.ac.jp

Few nucleon systems offer good opportunities to investigate nuclear interactions. The recent topic
of few-nucleon systems is to explore the properties of three-nucleon forces. We performed proton3He elastic scattering at incident proton energies of 65 and 100 MeV with a polarized proton beamin conjunction with the polarized 3He target system. In the conference, we present the data incomparison to the rigorous numerical calculations of four-nucleon scattering based on the various
nuclear potentials.

Spin in Nuclear Reactions and Nuclei / 148

Axial Vortical Effect and polarization of resonances in heavy-ion
collisions
Authors: Oleg TeryaevNone ; Valentin Zakharov1 ; George Prokhorov2
1

ITEP and MPTI

2

JINR

Corresponding Authors: vzakharov@itep.ru, teryaev@jinr.ru, prokhorov@theor.jinr.ru

The axial vortical effect is considered for currents corresponding to hadrons of spin 1/2, 1 and 3/2.
The density matrix approach suggested by Zubarev and developed by Becattini and collaborators isapplied. The duality between statistical description in usual Minkowski space and geometry in thespace with conical singularity is addressed. The interplay with anomalies calculations is outlined.
The possible phenomenological consequences for polarization of hadrons in heavy-ion collisions are
discussed.

Nucleon Helicity Structure / 149

The role of the chiral anomaly in polarized deeply inelastic scattering: Topological screening and emergent axion-like dynamics
Author: Andrey Tarasov1
Co-author: Raju Venugopalan 2
1

The Ohio State University

2

Brookhaven National Laboratory

Corresponding Author: tarasov.3@osu.edu

I’ll discuss the role of the chiral anomaly in deep inelastic scattering (DIS) of electrons off polarized
protons employing a worldline formalism, which is a powerful framework for the computation of
perturbative multi-leg Feynman amplitudes. I’ll demonstrate how the triangle anomaly appears at
high energies in the DIS box diagram for the polarized structure function g1 (xB , Q2 ) in both the
Bjorken limit of large Q2 and in the Regge limit of small xB . I’ll show that the infrared pole of theanomaly appears in both limits. I will introduce an effective action for spin dependent observables at
small x that follows from the cancellation of the infrared pole in the matrix element of the anomaly.
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This effective action, consistent with anomalous chiral Ward identities, is controlled by two dimensionful scales in Regge asymptotics. The first is the color charge squared per unit area, while thesecond is the pure Yang-Mills topological susceptibility.

Acceleration, Storage and Polarimetry of polarized Beams / 150

Measurement of Polarization Transfer in Møller Scattering
Authors: Michal Dragowski1 ; Marek Adamus2 ; Jacek Ciborowski1 ; Marco Dehn3 ; Joachim Enders4 ; Yuliya Fritzsche4 ;Valery Tioukine3
1

University of Warsaw, Faculty of Physics

2

National Centre for Nuclear Research

3

Johannes Gutenberg-Universitat Mainz, Institut fur Kernphysik

4Technische Universitat Darmstadt, Institut fur Kernphysik

Corresponding Author: mdragowski@fuw.edu.pl

Even though Møller scattering has been a subject of several precise experiments, studies of the final
spin state in Møller scattering of polarized electron beams offer a unique tool for testing the fundamnetal predictions of relativistic quantum mechanics. The aim of this work was to measure thepolarization transfer in Møller scattering (the ratio of the transverse polarization vector component
length of the electron in the final state to the incoming-beam polarization); it is, to our knowledge,
the first such measurement.
A dedicated Mott polarimeter was designed and constructed. In addition to the standard polarimeterlayout, it was equipped with a tagging detector, which was used for a coincidence trigger allowing torecord Møller scattering events. The reduction of background was achieved by an offline subtractionof data collected without the target in the polarimeter, as well as by event selections regarding
electron energy and timing of the signals from both recorded electrons.
The beam polarization, as well as the mean polarization of the electrons in the final state of symmetric
Møller scattering, were measured. The final results were calculated assuming an analyzing power
value obtained from a dedicated Monte Carlo simulation. The polarization transfer was measured for
two incident-beam polarization orientations with respect to the Møller scattering plane. The results
were found to be in agreement with the predictions of relativistic quantum mechanics.

Spin in Nuclear Reactions and Nuclei / 151

Explore double slit interference effect with linearly polarized photons in UPCs
Author: jian zhou1
1

Shandong University

Corresponding Author: jzhou@sdu.edu.cn

In this talk, I will disscuss the cos 2φ azimuthal angular correlation in rho^0 meson production in
ultraperipheral heavy ion collisions. The asymmetry essentially results from the linear polarizationof incident coherent photons, which just has been experimentally confirmed by the recent STARmeasurement. The asymmetries evaluated in the dipole model for rho^0 photoproduction at RHIC
and LHC energies are shown to be rather sizable, and is in reasonably good agreement with theSTAR measurement. I will show that the double slit interference effect plays a key role in yielding
the distinctive diffractive pattern of the observed asymmetry.
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Low energy spin physics with lepton, photon and hadron probes / 152

Spin effects in low-energy electron-nucleon scattering with twophoton exchange: Analysis based on 1/N_c expansion of QCD
Authors: Jose Goity1 ; Christian Weiss2 ; Cintia Willemyns3
1

Hampton University, Jefferson Lab

2

Jefferson Lab

3

University of Mons

Corresponding Author: cintia.willemyns@umons.ac.be

The transverse single-spin asymmetry in inclusive electron-nucleon scattering, e + N(S_T) -> e’ +X, represents a pure two-photon exchange observable and is of fundamental interest for exploringhigher-order QED effects in electron scattering. We compute this observable in the resonance region,
where excitation of Delta isobars occurs in both intermediate and final states. We employ a novel
theoretical method based on the large-N_c limit of QCD, which allows us to consistently combine
nucleon and Delta states and predict the elastic, inelastic, and inclusive spin-dependent cross section.
Our results aim at disentangling the different contributions of nucleon and Delta states organizingthem according to their 1/N_c scaling. The case of the target single spin asymmetry will be discussed
in detail. Our predictions could be tested in future measurements of electron-nucleon scatteringwith polarized targets in the few-GeV energy range. Such experiments would complement earlier
measurements of the inclusive single-spin asymmetry in the DIS regime (JLab, HERMES) and allow
one to study the unknown dependence of two-photon exchange dynamics on the energy/momentumof the probe.

Polarized Sources and Targets / 153

A High-Magnetic-Field Polarized 3He Target for JLab’s CLAS12
Author: James Maxwell1
1

Jefferson Lab

Corresponding Author: jmaxwell@jlab.org

Polarized 3 He nuclear targets have been invaluable surrogates for polarized neutron targets in spindependent scattering studies of the quark and gluon structure of matter. Traditional polarized 3 Hetargets have seen dramatic improvements in the last three decades, however they have been limitedin their use in spectrometers that utilize high-magnetic-field tracking systems, such as Jefferson
Lab’s CLAS12 spectrometer. Developments in high-magnetic-field metastability exchange opticalpumping of 3 He, recently brought to bear for a polarized 3 He ion source for RHIC and the EIC, offera path to a high-field polarized 3 He fixed target. By combining these techniques with a double-cellcryogenic target design, such as the one used for the MIT-Bates 88-02 experiment, polarization andtarget density comparable to traditional polarized 3 He targets can be reached while within a highmagnetic field environment. We will discuss the conceptual design for such a target, preview aconcept for achieving polarization transverse to the incident beam with this method, and show ourprogress in this target’s development.

Joint BSM - Accelerator - Future Session EU timezone / 154

A new search for time-reversal symmetry-breaking in muon decays
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Author: Sohtaro Kanda1
1

KEK

Corresponding Author: kanda@post.kek.jp

One of the key open questions on the nature of the neutrino is whether it is a Dirac or a Majorana
particle. If the neutrino is a Majorana particle, then the interference terms that break the timereversal symmetry of muon decay appear as the transverse spin polarization of the decay electron[1]. Experiments have been performed at Paul Scherrer Institute to measure the spin polarizationof positrons in positive muon decays, using Bhabha scattering and annihilation-in-flight [2]. No
significant transverse polarization of decay positrons has been observed so far, and experimentswith higher sensitivity can push the scope of searches for physics beyond the Standard Model. This
topic is revisited by investigating the possibility of a new experiment using a high-intensity pulsed
muon beam at J-PARC. As a result of the Monte-Carlo simulations, the prospect of improving themeasurement precision by at least one order of magnitude was obtained. In this contribution, theoutline of the new experiment and the design of the polarimeter will be discussed.
[1] M. Doi, T. Kotani, H. Nishiura, K. Okuda, and E. Takasugi, Prog. Theor. Phys. 67, 281 (1982).
[2] N. Danneberg et al., Phys. Rev. Lett. 94, 021802 (2005).

Transverse Momentum Structure (TMD) / 155

Extracting the Λ polarizing Fragmentation Function from Bellee+ e− data within the TMD formalism.
Authors: Marco Zaccheddu1 ; Leonard GambergNone ; Umberto D’Alesio2 ; Francesco Murgia3
1

Istituto Nazionale di Fisica Nucleare, Università degli Studi di Cagliari

2

University and INFN Cagliari

3

INFN Cagliari, Italy

Corresponding Author: marco.zaccheddu@ca.infn.it

Data from the Belle Collaboration for associated production (with a light unpolarized hadron) andsingle-inclusive production of transversely polarized Λ-hyperons in e+ e− annihilation processes allowed to extract, for the first time, the Λ polarizing fragmentation function, by adopting a simplified
TMD approach.
Recent theoretical developments on the computation of cross sections for single-inclusive hadronproduction in e+ e− annihilation, within a Soft Collinear Effective Theory approach, combined with
the CSS formalism for the double-hadron production case, can be used to perform a renewed analysis, adopting a proper TMD factorization scheme. Preliminary results and a comparison between
the two analyses are presented.

Transverse Momentum Structure (TMD) / 156

Beam spin asymmetries of π + π 0 and π − π 0 dihadrons from SIDIS
at CLAS12
Author: Christopher Dilks1
1

Duke University

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Corresponding Author: dilks@jlab.org

Spin asymmetries provide a wide range of insights into nucleon structure andhadronization. Recent measurements of beam spin asymmetries of π + π −dihadrons from SIDIS at CLAS12 provide the first empirical evidence of a nonzeroG⊥
1 , the parton helicity-dependent dihadron fragmentation function(DiFF) encoding spin-momentum correlations in hadronization. These measurements
have been extended to help further characterize H1⊥ andH1< , the DiFFs dependent on parton transverse spin, via a
multidimensional partial wave analysis, giving access to the dependence on theinterference of dihadrons of particular polarizations. Reconstruction ofπ 0 s allows for further extension of these measurements to π + π 0 andπ − π 0 dihadrons. The DiFFs describing π + π − production differ
from those describing π + π 0 and π − π 0 production, which involve
different quark flavors along with a strong suppression of the exclusive
diffractive contribution. This presentation will focus on comparisons of beamspin asymmetries for these three dihadron flavors, which will help shed light ona more comprehensive picture of dihadron fragmentation.

Polarized Sources and Targets / 158

A versatile bulk superconducting MgB2 cylinder for the production of holding magnetic field for polarized fuels and targets
Authors: Luca Barion1 ; GIuseppe Ciullo2 ; Marco Contalbrigo1 ; Lucia Del Bianco 3 ; Filippo Lanaro4 ; Paolo Lenisa5 ;Federico Spizzo3 ; Marco Statera6 ; Giuseppe Tagliente 71

INFN-Ferrara

2

INFN Ferrara and Physics and Earth Science Department of the University of Ferrara

3

INFN-Ferrara AND Dipartimento di Fisica e SdT - University of Ferrara

4

INFN-Fe AND Dipartimento di Fisica e Scienze della Terra - University of Ferrara

5

University of Ferrara and INFN

6

LASA-INFN Milano, Italy

7

INFN-sezione di Bari

Corresponding Authors: spzfrc@unife.it, giuseppe.tagliente@ba.infn.it, dlblcu2@unife.it, mcontalb@fe.infn.it,
ciullo@fe.infn.it, filippo.lanaro@edu.unife.it, marco.statera@mi.infn.it

The production of an internal magnetic field in a compact space is a challenging problem and a versatile solution is being pursued. The property of a hollow superconductor is exploited in order to trapa specific configuration of magnetic field, which could shield the interior from externally appliedfields. This can be achived applying the desired magnetic configuration during the cooling process
through the transition temperature.
This solution, in the longitudinal field configuration, would be useful for polarized fuel for nuclear
fusion test. In the transverse field configuration, instead, would be useful for transversely polarized
nuclear target.
A bulk superconducting MgB2 cylinder has been characterized measuring the interior field retention, the capability to exclude an externally applied field and the corresponding long-term stability
performance. The measurements have been done just in its center at 1 T transverse magnetic fieldat around 13 K.
The present programs are focused on mapping the trapped field along the symmetry axis, at higher
magnetic field, and at lower working temperature in a transverse magnetic field.
Afterwards the cylinder will be tested in a longitudinal field, but also prepared in a transverse field
and then immersed in a longitudinal field to test its capability on shielding the latter.
In the context of an electron scattering experiment, such a solution will minimize beam deflectionand energy loss of the reaction products, while also will eliminate the heat load to the target cryostat
from current leads that are required for superconducting electromagnets.
In the context of polarized fuel for fusion its use is straightforward, because the system can trap the
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magnetic field required during fuel production, and then provide the holding field for its transfer infusion test facilities.

Form Factors and GPDs / 159

Three-loop corrections to the quark and gluon decomposition of
the QCD trace anomaly and their applications
Author: Kazuhiro Tanaka1
1

Juntendo University

Corresponding Author: kztanaka@juntendo.ac.jp

In the QCD energy-momentum tensor T µν , the terms that contribute to physical matrix elements
are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes
the renormalization due to the interactions among quarks and gluons, although the total tensor T µν
is not renormalized thanks to conservation of energy and momentum. We show that, through therenormalization, each of the quark and gluon parts of T µν receives a definite amount of anomalous
trace contribution, such that their sum reproduces the well-known QCD trace anomaly. We provide
a procedure to derive such anomalous trace contributions to all orders in perturbation theory, andpresent the corresponding explicit decomposition formulas up to three-loop order in the (modified)minimal subtraction scheme in the dimensional regularization. We apply our three-loop formulas of
the quark/gluon decomposition of the trace anomaly to calculate the anomaly-induced mass structure of nucleons as well as pions. Another application of our three-loop formulas is a quantitative
analysis for the constraints on the twist-four gravitational form factors of a hadron, C̄q,g , which receive much attention in connection with the force distribution inside the nucleon and the nucleon’stransverse spin sum rule. This talk is based on our work, JHEP 1901 (2019) 120, and some additional
results.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 160

The MOLLER experiment
Author: Ciprian Gal1
1

Stony Brook University

Corresponding Authors: cghosh@umass.edu, ciprian@jlab.org

The precision extraction of the weak mixing angle at low momentum transfer can significantly constrain extensions to the Standard Model. One such measurement will be undertaken by the MOLLER
collaboration starting in 2025. Using longitudinally polarized electrons scattering from unpolarized
electrons in a liquid hydrogen target the experiment will be able to measure the approximately 34
parts per billion parity violating asymmetry to a precision of 2%. Such high precision requires finecontrol of systematics and innovations in magnet and detector design. The status of the project,experimental description and potential implications of the result will be discussed.

Spin in Nuclear Reactions and Nuclei / 161

Weak charge distribution of 208Pb
Author: Ciprian Gal1

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1/ Book of Abstracts

Stony Brook University

Corresponding Authors: donald.jones@temple.edu, ciprian@jlab.org

While the electromagnetic charge distribution of protons inside nuclei has been well determinedusing electron scattering experiments, significant progress still needs to be made to reach the samelevel of precision for neutrons. The parity violating asymmetry in longitudinally polarized elastic
electron-nucleus scattering is sensitive to the neutron RMS radius. The PREX-2 collaboration has
completed a measurement using this technique looking at the neutron-rich 208 Pb nucleus. The clean
theoretical connection between the parity violating asymmetry and other parameters of the nuclear
equation of state allows for comparisons with other measurements (such as neutron star radii). In
this talk we will present the recently published high precision result from data collected in 2019using the CEBAF accelerator at Jefferson Lab.

Spin in Nuclear Reactions and Nuclei / 162

CREX: The Calcium weak Radius Experiment
Author: Ciprian Gal1
1

Stony Brook University

Corresponding Authors: tianye@jlab.org, ciprian@jlab.org

The 48 Ca nucleus provides an important testing ground for models (both density functional andab-initio) trying to describe the arrangement of both protons and neutrons in nuclei. The parity
violating electron scattering asymmetry from the unpolarized 48 Ca nucleus gives direct access to
its weak form factor. Using data collected with the CEBAF accelerator at Jefferson Lab in 2020 the
CREX collaboration has completed a blinded analysis of this quantity. This talk will describe theexperiment, data analysis and systematic control, as well as the implications of this result on our
understanding of nuclear matter.

Joint TMD - GPD - HELCITY - Future session EU timezone / 163

TMDs and EIC impact studies
Authors: Chiara BissolottiNone ; Alessandro Bacchetta1 ; Marco Radici2
1

Università di Pavia and INFN

2

INFN, Sezione di Pavia

Corresponding Authors: matteo.cerutti02@universitadipavia.it, chiara.bissolotti01@universitadipavia.it

Semi-Inclusive Deep-Inelastic Scattering (SIDIS) is one of the processes that allow us to extract information about Transverse Momentum Distributions (TMDs) and will be the main channel to access
TMDs at the future Electron Ion Collider (EIC).
We provide an estimate of the impact that EIC data will have on unpolarized Transverse-Momentum
Dependent (TMD) Parton Distribution Functions (PDFs) and Fragmentation Functions (FFs). We
performed a study that shows that including EIC pseudo data in a global fit allows us to better determine the non-perturbative parameters of unpolarized TMD PDFs and FFs, which are much moreconstrained than in the global fit performed by the Pavia group in 2017.

Transverse Momentum Structure (TMD) / 164
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Progress in the extraction of unpolarized TMDs from global data
sets
Author: Andrea Signori1
Co-authors: Matteo Cerutti 1 ; Giuseppe Bozzi 1 ; Marco Radici 2 ; Chiara Bissolotti ; Valerio Bertone 3 ; Alessandro
Bacchetta 4
1

University of Pavia and INFN

2

INFN, Sezione di Pavia

3

Irfu, CEA, Université Paris Saclay

4

Università di Pavia and INFN

Corresponding Authors: matteo.cerutti02@universitadipavia.it, andrea.signori@unipv.it

We review the recent progress on the extraction of unpolarized TMD PDFs and TMD FFs from global
data of Semi-Inclusive Deep-Inelastic Scattering, Drell-Yan and Z boson production. In particular,
we address the tension between the low-energy SIDIS data and the theory predictions, and explore
the impact of the very precise LHC data on the fit results.

Transverse Momentum Structure (TMD) / 165

Transverse Single-Spin Asymmetries of Midrapidity Direct Photons and Neutral Mesons at PHENIX
Author: Christine Aidala1
1

University of Michigan

Corresponding Author: caidala@umich.edu

Recently published measurements from the PHENIX experiment at the Relativistic Heavy Ion Collider will be presented for the transverse single-spin asymmetries (TSSAs) of direct photons, neutralpions, and eta mesons produced at midrapidity in 200 GeV proton-proton collisions. As hadrons, neutral pions and eta mesons are sensitive to nonperturbative spin-momentum correlations both within
the proton and in the process of hadronization; at midrapidity they probe the dynamics of gluons
along with a mix of quark flavors. The direct photon TSSA measurement instead isolates initialstate spin-momentum correlations within the proton and at midrapidity provides a clean probe of
the gluon dynamics in transversely polarized protons. All three of these results will help to constrain the collinear twist-3 trigluon correlation function. The direct photon result is the first-evermeasurement of this observable from a hadron collider, and all three of the measurements represent
the final, definitive results for these observables from the PHENIX experiment, which completed
data taking with polarized beams in 2015.

Acceleration, Storage and Polarimetry of polarized Beams / 166

Spin depolarization in high energy electron storage rings: stochastic differential equations, the reduced Bloch equation and theinvariant-spin-field approximation
Authors: Oleksii Beznosov1 ; Desmond Barber2 ; James Ellison1 ; Klaus Heinamann1
1

University of New Mexico (UNM), Department of Department of Mathematics and Statistics

2

Deutsches Elektronen-Synchrotron (DESY)

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Corresponding Author: beznosov@math.unm.edu

A spin distribution in a high energy e+ or e− storage ring is governed by a (6 + 1) dimensional
linear Fokker-Planck-type equation known as the full Bloch equation. Its reduction, the reduced
Bloch equation (RBE), is the spin-orbit diffusion equation which takes into account just those terms
in the spin-orbit dynamics that suffice for calculating the spin-depolarization rate. While the RBE
gives the full picture of the depolarization phenomenon, it has limitations, both in terms of analysis
and numerical simulations. Here we introduce a framework for studying the Bloch equation basedon a stochastic differential equation (SDE). The framework combines SDEs, modelling the spin-orbit
motion of the electrons(positrons), Fokker-Planck type equations for orbit and spin-orbit density
functions, and approximations for studying them. The SDEs in the framework are derived fromthe Lorenz force law coupled with Thomas-Bargmann-Michel-Telegdi spin precession and, as thename suggests, include a stochastic process modelling the effect of synchrotron radiation. This SDE
framework reproduces the known equations modelling the depolarization phenomenon, like theBloch equation and the Derbenev-Kondratenko (DK) formulas. It can also be used, as we do here,
either to generalize the DK formulas and the Bloch equation, or to simplify the latter to a form thatmakes it amenable for solution by numerical methods.
The Bloch equation models the spin distribution as a three-scale time dependent process. The firstscale comes from the rapidly varying transverse motion, governed by accelerator optics; the second scale arises from the classical spin precession, with rates varying with reference energy of theelectron bunch; and finally the synchrotron motion, which is slowly varying yields the last scale.
Coupling between the synchrotron motion and transverse betatron motion introduces spin-orbit
resonances that have a devastating effect on spin-polarization in most optical settings and referenceenergies. Multiple scales involved require hybrid approaches. We will present three approaches toapproximate solutions of the Bloch equation that can be hybridized within the SDE framework. The
first approach uses perturbation theory and delivers the results consistent with formalism previously
derived from QED. The second approach is built on averaging analysis of the slowly varying form of
the SDEs and brings in the effective models to study spin-depolarization. The third approach is thenumerical integration of the Bloch equations with a spectral method based on Fourier-Chebyshev
expansions.
Finally, at the end of talk we use a simple model that contains most of the difficulties present inequations for a realistic accelerator. We will demonstrate the efficacy of the SDE framework and theapproximations. We finish by presenting an approach in which coefficients in these equations areaveraged to produce a so-called effective Bloch equation and then present a scheme for the numericalintegration of the latter.

Fundamental Symmetries and and Spin Physics Beyond the Standard Model / 167

CP-violating gluon operators and neutron EDM from the QCD
instanton vacuum
Author: Christian Weiss1
1

Jefferson Lab

Corresponding Author: weiss@jlab.org

Experimental studies of hadronic CP-violation rely on theoretical calculations of the hadronic matrix
elements of higher-dimensional QCD operators representing the effects of the CP-violating shortdistance dynamics at the hadronic scale. We report about a recent calculation of the spin-dependent
nucleon matrix element of Weinberg’s dimension-6 CP-odd gluon operator f abc (F̃µν )a (F µρ )b (F νρ )cusing the instanton picture of the QCD vacuum [1]. In leading order of the instanton packing fraction, the dimension-6 operator is effectively proportional to the topological charge density (F̃µν )a (F µν )a ,whose nucleon matrix element is given by the flavor-singlet axial charge and constrained by theU (1)A anomaly. The nucleon matrix element of the dimension-6 operator is obtained substantiallylarger than in other estimates, because of the strong localization of the nonperturbative gluon fields
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in the instanton vacuum. We comment on the neutron EDM induced by the dimension-6 gluon
operator. We discuss the connection of the CP-violating operators with other operators describing
nucleon spin structure in deep-inelastic processes.
[1] C. Weiss, Phys. Lett. B 819 (2021) 136447

Spin in Nuclear Reactions and Nuclei / 168

Spin contents of Na isotopes towards driplines
Author: Takaharu Otsuka1
Co-author: Noritaka Shimizu 1
1

University of Tokyo

Corresponding Author: otsuka@phys.s.u-tokyo.ac.jp

The structure evolution of neutron-rich isotopes provides with many intriguing facets. Recently,
we presented [1] how such evolution occurs in F-Ne-Na-Mg isotopes up to their neutron driplines,
by using an ab initio effective nucleon-nucleon (N N ) interaction derived from the chiral Effective
Field Theory of QCD [2]. In this presentation, we shall report some features of the spin contents
obtained quite recently by extending this approach. These features are focused on because of themain interest of the conference. We thus discuss the magnetic moments of Na isotopes up to theirdripline, in agreement with experimental values [3].
The wave functions used in this work can produce another nice agreement with experiment forthe charge/matter radii and the quadrupole moments, as well as the ground-state energies [1]. The
dripline is located at 39 Na, being most likely consistent with experiment [1,4].
One of the remarkable findings is that the magnetic moments of the ground states of Na isotopes
up to 31 Na can be well described by free spin g-factors (gs ). On the other hand, it appears thatthe orbital g-factors (gl ) are changed from the free values by an isovector shift of 0.2. Such an
isovector shift of the orbital g-factors is quite usual, and is ascribed to the meson effect which can beneeded independently of the nuclear structure calculation. On the other side, the spin quenching has
been considered to be due to the 2p2h excitations across the relevant magic gap (core polarizationor configuration mixing), which are explicitly included, in our calculation, between the sd and pf
shells thanks to the present ab initio effective N N interaction capable of describing such cross-shell
excitations. We note that only the present interaction may have this capability among various ab
initio interactions proposed so far, due to its derivation by the EKK method [5]. It is of interest to
examine predicted values for Na isotopes beyond 31 Na.
The predicted magnetic moments of exotic Na isotopes indeed point to strongly deformed shapes,
as expected in the scenario presented in Ref. [1]. The neutron spin contents of exotic Na isotopes
are quite small up to the dripline nucleus. The proton spin contents are more sizable, but differ fromthose in the single-particle picture. Thus, the exotic Na isotopes are expected to be a very interestingdomain in the nuclear chart, including their magnetic properties.
[1] N. Tsunoda, T. Otsuka, K. Takayanagi, {\it et al.}, Nature {\bf 587}, 66 (2020).
[2] R. Machleidt and D. R. Entem, Phys. Rep. {\bf 503}, 1 (2011).
[3] National Nuclear Data Center’s ‘Evaluated Nuclear Structure Data File’ (http://www.nndc.bnl.gov/ensdf/).
[4] D. S. Ahn, {\it et al.}, Phys. Rev. Lett. {\bf 123}, 212501 (2019).
[5] N. Tsunoda, K. Takayanagi, M. Hjorth-Jensen, and T. Otsuka, Phys. Rev. C {\bf 89}, 024313(2014).

Transverse Momentum Structure (TMD) / 170

Fragmentation function measurements from Belle
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Authors: Gunar SchnellNone ; Ralf Seidl1 ; Belle CollaborationNone
1

RIKEN

Corresponding Author: gunar.schnell@desy.de

Electron-positron annihilation into hadrons is one of the fundamental tools for studying non-perturbative
QCD effects. Fragmentation functions, describing the formation of hadrons from partons, are an indispensable tool in the interpretation of hadron-production data, e.g., in the investigation of nucleon
structure via semi-inclusive deep-inelastic scattering. The cleanest process to access fragmentation
functions is hadron production in electron-positron annihilation. However, little information canbe derived on charge-separated fragmentation functions from single-inclusive hadron production. A
better handle on the flavor contributions can be gotten by flavor correlations or tagging: the hadrontype in one hemisphere puts constraints on the parton flavor in the other hemisphere and thus on theflavor decomposition of the hadronization process. This can be exploited in inclusive hadron-pair
production in electron-positron annihilation. While two hadrons in the same hemispheres, e.g., originating from the same parton, open an avenue to an unusual class class of fragmentation functions,dihadron fragmentation functions, two hadrons in opposite hemispheres can be used for flavor andpolarization tagging of single-hadron fragmentation functions. These scenarios have recently been
subject to renewed studies at the Belle experiment. As one part of this contribution, without explicit
relation to polarization effects, the dependences of the production cross section of pairs of identified
light mesons (charged pions and kaons) as well as of (anti)protons on the individual z of the hadrons
as well as on alternative scaling variables will be presented. Furthermore, the first measurement of
the transverse-momentum dependence of single-hadron fragmentation, for charged pions, kaons aswell as for protons, will be discussed.
The Belle experiment at the asymmetric KEKB electron-positron collider has already published several ground-breaking results on fragmentation functions, among others, the first measurement of
azimuthal correlations for pairs of almost back-to-back charged pions related to the novel Collins
fragmentation effect. The latter is one example of polarization dependence in hadronization despite
an unpolarized initial state. Recently, these Collins modulations for charged pions have been revisited in the study of their transverse-momentum dependence. The analysis was also expanded toinclude for the first time neutral pions as well as eta mesons. An additional novel polarization effectis the formation of transversely polarized Lambda hyperons in the fragmentation process. Transversely polarized hyperons have been produced copiously in unpolarized proton-proton collisions,however, the question of the origin of these partially rather large polarizations has remained unanswered. One possibility is a novel fragmentation function, which was the focus of a recent study at
Belle. The results for the production of transversely polarized Lambda hyperons and the of abovementioned Collins modulations will be discussed in the second part of this contribution.

Plenary Presentations / 172

Opening remarks
Corresponding Authors: goto@bnl.gov, uesaka@riken.jp

Plenary Presentations / 173

Theory of muon g-2
Author: Bogdan MALAESCU1
1

CNRS, LPNHE

Corresponding Author: malaescu@in2p3.fr

The longstanding discrepancy between the measured and the predicted values of the anomalous
magnetic moment of the muon, aµ = (g-2)/2, is one of the most intriguing potential hints of newPage 74

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physics in particle physics. After a brief introduction, the status of the theoretical prediction of g-2
will be presented, with some focus on the contributions yielding the dominant uncertainties. The
results presented here are based mainly on the White Paper (arXiv:2006.04822) of the Muon g-2
Theory Initiative.

Plenary Presentations / 174

Progress on Lattice QCD studies on the spin physics
Author: Constantia Alexandrou1
1

University of Cyprus and The Cyprus Institute

Corresponding Author: alexand@ucy.ac.cy

Resent results obtained using state-of-the-art lattice QCD simulations on the nucleon spin decomposition will be reviewed. The results include valence and sea quark and gluon contributions. Openissues in particular connected to the fixing and renormalisation will be discussed.

Plenary Presentations / 175

ELI-NP project overview
Author: Calin Alexandru Ur1
1

ELI-NP / IFIN-HH

Corresponding Author: calin.ur@eli-np.ro

Extreme Light Infrastructure - Nuclear Physics (ELI-NP) is a new research infrastructure installed in
Bucharest-Magurele (Romania) dedicated to Nuclear Photonics with extreme photon beams. At ELINP high-power laser and gamma beams with unprecedented characteristics will be provided to be
used for nuclear physics, laser plasma physics, quantum electrodynamics, material science researchand related fields.
The high-power laser system consisting of 2 x 10 PW lasers with ultra-short pulses will reach irradiance values as high as 1023 W/cm2 and will create ultra-dense, ultra-short, high-energy ion beams
as well as coherent X-ray sources. The operation of the laser system at 10 PW has recently marked
a world premiere in the field of high-power lasers.
The gamma beams to be delivered at ELI-NP will exhibit high spectral density of about 104 photons/s/eV, average relative bandwidth of less than 0.5%, continuously tuneable energy up to about
20 MeV, linear polarization of more than 95%.
The experimental setups are currently under commissioning and the first experiments with highpower lasers aim at measuring the magnitude and scaling of the achievable laser intensity via lasergamma conversion efficiency, finding new ion acceleration schemes and achieving a better understanding and control of high-intensity laser-driven ion sources.
The outstanding characteristics of the gamma beams that will be provided at ELI-NP are opening
new perspectives in Nuclear Photonics. Nuclear Resonance Fluorescence experiments will allow for
the direct, model-independent determination of key information about the nuclear excited states,
such as: excitation energy, spin quantum numbers, parities, branching ratios as well as level widths
and gamma decay branching ratios. Photonuclear reactions experiments will largely benefit of theoutstanding features of the gamma beams allowing for the study of electromagnetic dipole responseof rare nuclei available in nature in extremely low quantities, such as p-nuclei.
A broad research program on technologies for biomedical applications, anchored in the unique ELINP capabilities, is currently being developed and addresses topics, such as: production of radiotherapy relevant nuclear beams, radiobiological effects of laser and gamma nuclear beams, medical
imaging research with laser X-ray sources and medical isotope production research with laser-driven
nuclear beams.
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An overview of the ELI-NP research infrastructure and of selected research topics to be investigatedat ELI-NP will be given.

Plenary Presentations / 176

Polarization aspects of CMB
Author: Sophie Henrot-Versillé1
1

IJCLab, IN2P3/CNRSCorresponding Author: sophie.versille@ijclab.in2p3.fr

I will present some aspects of the measurements of the polarization of the Cosmological Microwave
Background (CMB). In particular, I will detail what we have deduced about the cosmological parameters of the LambdaCDM concordance model and its extensions through the observation of the
CMB polarization with the Planck satellite. I will also discuss future projects that aim to increase
the precision of these measurements. Some of them are under construction or design, either on the
ground or in space: the Simons observatory, CMB-S4 and LiteBIRD. For these, I will focus mainlyon the predictions of the B-modes observation, with emphasis on the expected results on our understanding of fundamental physics, and in particular on the physics of the primordial universe, andthe mass of neutrinos.

Plenary Presentations / 177

Spin Polarization Effects in Heavy Ion Collisions
Author: Zuo-tang Liang1
1

Shandong University

Corresponding Author: liang@sdu.edu.cn

itle: Spin polarization effects in Heavy Ion Collisions
Presenter: Zuo-tang Liang (Shandong University)
Abstract:
In non-central high energy heavy ion collisions, the colliding system possesses a huge orbital angularmomentum along the normal direction of the reaction plane. Due to the spin orbit interaction in therelativistic quantum system, such a huge orbital angular momentum leads to the spin polarization ofquarks and anti-quarks in the quark matter system produced in the collision. Such an effect, known
as the global polarization effect (GPE), was predicted many years ago and has been confirmed by theSTAR collaboration at RHIC. The discovery of GPE by the STAR collaboration opens a new window
in heavy ion physics in general and in studying the properties of quark-gluon plasma in particular.
In this talk, I will briefly review the original ideas and calculations that lead to the prediction andsummarize progresses and problems in related aspects.

Plenary Presentations / 178

Spin-polarized exotic nuclei and beta-NMR: from fundamental
interactions, via nuclear structure, to material science, biology
and medicine.
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Author: Magdalena Kowalska1
1

CERN

Corresponding Author: kowalska@cern.ch

This talk is devoted to versatile studies with spin-polarized radioactive nuclei, which make use ofasymmetric emission of decay radiation. This feature is often combined with nuclear magnetic resonance, resulting in the beta-NMR technnique, which is up to 10 orders of magnitude more sensitive
than conventional NMR. In my CERN-ISOLDE experiment we have just used it to determine magnetic dipole moments of short-lived nuclei with part-per million accuracy.
In this talk I will introduce the principles of laser polarisation, asymmetric beta decay, and betaNMR. I will then concentrate on recent highlights from different fields of research: mirror decays
for CKM-matrix unitarity studies, beta-NMR in solids for material science and in liquids to determine accurate nuclear magnetic moments, and to perform studies in chemistry and biology. I will
also mention the gamma-MRI approach, which can combine the high sensitivity of PET and SPECT
techniques with high spatial resolution of MRI.

Plenary Presentations / 179

An EDM search experiment with ultracold polyatomic molecules
Author: John Doyle1
1

Harvard University

Corresponding Author: doyle@physics.harvard.edu

Polar molecules, due to their intrinsic electric dipole moment and their controllable complexity, are a
powerful platform for precision measurement searches for physics beyond the standard model (BSM)and for quantum simulation/computation. This has led to many experimental efforts to cool andcontrol molecules at the quantum level. I will discuss our results on the laser cooling of molecules
into the ultracold regime, the search for the electric dipole moment of the electron (EDM), andfuture prospects for the use of polyatomic molecules to greatly improve the search for the EDM,
which would broadly probe for - in the not to distant future - PeV level CP violating new particles.
I will briefly discuss the creation of an optical tweezer array of ultracold CaF molecules, as wellas the search for the EDM using cold ThO molecules (the ACME experiment, which has alreadybroadly probed for > 1 TeV physics). I will focus on the prospects for laser cooling of the polyatomic molecules, in particular the laser cooling of YbOH for a new experiment, dubbed PolyEDM.
More broadly, polyatomic molecules have attracted new focus as potential novel quantum resourcesthat have distinct advantages (and challenges) compared to both atoms and diatomic molecules. I
will discuss how some key features of polyatomic molecules can be used to enhance applications
in fundamental symmetry tests, searches for dark matter, and the search for CP-violating BSM
physics.

Plenary Presentations / 180

Crystallography of Dynamically Polarized Proteins with Polarized Neutron Beams
Author: Josh Pierce1
1

Oak Ridge National Laboratory

Corresponding Author: piercejj@ornl.gov

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Protein crystallography is an established technique for determining the structure of many protein
systems. X-ray protein crystallography is the dominant technique, as the incredibly high flux ofmodern light sources allows researchers to collect data very quickly using very small crystals. In
comparison, neutron crystallography has many unique advantages (due the neutron’s sensitivity
to isotopes and light nuclei) but suffers from the low flux available at neutron sources. The spin
dependence of slow neutron scattering provides an opportunity to overcome the flux limitations ofneutron sources, expanding the number of protein systems that can be studied, improving the signal
to noise, and enabling novel measurement techniques to determine the location of hydrogen atoms.
At Oak Ridge National Laboratory, a program has been underway to develop Dynamic Nuclear Polarization (DNP) techniques, and apply them to neutron scattering, especially Neutron Macromolecular
Crystallography of proteins. The status and results of the Dynamic Nuclear Polarization program at
Oak Ridge National Laboratory will be discussed, with an emphasis on the use of DNP to enhancemeasurements of diffraction from protein crystals.

Plenary Presentations / 181

Theoretical studies on the 3D structure of the nucleon
Author: Barbara Pasquini1
1

University of Pavia and INFN, Pavia

I will discuss recent progress in the theoretical investigation of the partonic structure of the nucleon
in terms of generalized parton distributions and transverse momentum dependent parton distributions. In particular, I will highlight the information encoded in these functions on the spin andmultidimensional partonic structure of the nucleon.

Plenary Presentations / 182

Experimental studies on the high-energy spin physics in the fixedtarget experiments
Author: Fabienne KUNNE1
1

CEA Saclay IRFU DPhN

Corresponding Author: fabienne.kunne@cea.fr

Results on high energy spin physics obtained at various facilities with fixed-target experiments will
be presented. This includes measurements at JLab, Compass at CERN and HERMES at DESY. The
topics covered are essentially the parton helicity and transversity, Sivers effect, GPDs and HEMPs.
The extracted polarized PDFs and TMDs will be shown.

Plenary Presentations / 183

Theoretical studies on the nucleon helicity structure
Authors: Christopher Cocuzza1 ; nobuo sato2
1

Temple University2

odu

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Corresponding Author: tug83224@temple.edu

In this talk we will provide an overview of the current theoretical status of observables that provide
access to helicity PDFs and summarize the opportunities and challenges at the future EIC.

Plenary Presentations / 184

High-energy polarized proton experiments in the USA
Author: Kenichi IMAI1
1

JAEA/Kyoto

Corresponding Author: ken1.imai@gmail.com

Great progress in high energy polarized proton experiments was made in the USA. Historically theseexperiments were carried out mainly at ZGS, LAMPF, AGS, FNAL, first with polarized targets andthen with polarized proton beams from 1970s. These efforts are followed now at RHIC. I will briefly
review the progress of the spin physics with high energy polarized protons, especially in relation
with the contribution of Prof. Alan Krisch and Dr. Aki Yokosawa who have passed away rather
recently. In this spin symposium, it is meaningful to remember their achievements in the progressof the high energy spin physics.

Plenary Presentations / 185

High-energy polarized proton accelerators in the USA
Author: Thomas Roser1
1

BNL

Corresponding Author: roser@bnl.gov

The acceleration and storage of high energy polarized proton beams has made tremendous progressover the last fifty years challenging along the way the technologies, precision and the understandingof the beam dynamics of accelerators. After a brief summary of the development and history ofpolarized proton beam acceleration and the key contributions made by Ernest Courant and Satoshi
Ozaki I will focus on the highest energy polarized proton collider, RHIC, and on the possibility ofaccelerating polarized beams to even higher energies in the future.

Plenary Presentations / 186

Experiments with photon beams at the HIGS facility
Author: Calvin Howell1
1

Duke University and the Triangle Universities Nuclear Laboratory

Corresponding Author: howell@tunl.duke.edu

The angular-momentum selectivity in photon-induced nuclear reactions enables strategic investigations of nuclear and nucleon structure via excitation of the internal electric charge and current distributions as expressed through single-particle and collective motion responses. The narrow energy
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resolution and high polarization of laser Compton gamma-ray (γ-ray) beams offer a complementaryprobe to bremsstrahlung beams for studying nuclear phenomena. The High Intensity Gamma-ray
Source (HIγS) at the Triangle Universities Nuclear Laboratory (TUNL) is the highest intensity Compton gamma-ray source in the world [1]. The γ-ray beam at HIγS is produced by Compton-back scattering of electrons from photons inside the optical cavity of a storage-ring based free electron laser.
This unique facility provides circularly and linearly polarized γ-ray beams with beam polarization
greater than 95% and beam energy resolution as low as 2% over the energy range from 2 to 110 MeV.
These beam capabilities enable a broad research program that includes nuclear structure and reactions, nuclear astrophysics, fission, few-nucleon reaction dynamics, nucleon structure, and detector
R&D.
An overview of the current research program at HIγS will be presented that includes highlights ofrecent results in several research areas, e.g., studies of collective electromagnetic nuclear responses
using nuclear resonance fluorescence, photon-induced reactions important in nuclear astrophysics,
photofission, few-nucleon reaction studies, and the determinations of the low-energy electric andmagnetic structure parameters of the nucleons using Compton scattering. The talk will conclude
with a discussion about future directions for the HIγS research program and the facility.
[1] H.R. Weller et al., “Research Opportunities at the Upgraded HIGS Facility,” Prog. Part. Nucl. Phys.
62, 257 (2009).
This work is supported in part by the U.S. Department of Energy Office of Nuclear Physics under
grant no. DE-FG02-97ER41033.

Plenary Presentations / 187

LEPS experiments with polarized photons
Author: Jung Keun Ahn1
1

Korea University

Corresponding Author: ahnjk@korea.ac.kr

A linearly polarized photon beam acts as a filter to disentangle the production mechanisms andsuppress background processes in the photoproduction of mesons and baryons. Compton backscattering of laser light off the 8 GeV electrons circulating in the SPring-8 storage ring provides a highintensity beam of linearly polarized photons in a range of 1.4 - 2.9 GeV. The LEPS facility featured
a large dipole spectrometer and operated in the last 20 years. LEPS data encompasses final states
produced forward, such as K + , K ∗ , and ϕ from photoproduction and manifested in experimental
observables such as the cross-section and beam asymmetry. In addition, associated hyperon production with K ∗ is fascinating to unveil the nature of Λ(1405). The LEPS2 facility, consisting of alarge solenoid magnet and a time projection chamber, has recently completed its first phase of beamcommissioning and physics running. Analysis effort of the first dataset is now underway. We will
present selected recent highlights with LEPS and the prospects of the LEPS2 facility.

Plenary Presentations / 188

Progress on the new solid polarized target by using the symmetryof Perovskite structure
Author: Masataka Iinuma1
1

Hiroshima University

Corresponding Author: iinuma@hiroshima-u.ac.jp

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It is widely known that a solid polarized target is a powerful device for researches in spin physics,
such as investigation of spin structure of nucleons, nuclear structure, and spin correlation in nuclear reactions. Although about 50 years have already passed since the beginning of studies on
the Dynamic Nuclear polarization(DNP), the solid polarized targets are still limited to protons anddeuterons in practical beam experiments. A possible method for breaking the above situation is the
DNP by using the symmetry of Perovskite structure. This method holds possibilities for realizing
the practical polarized targets of nuclei with high quadrupole moments, which are expected as completely new tools for opening up potentialities in Spin Physics. The NOPTREX collaboration applies
it to the development of polarized lanthanum(La) targets for discovery of Time-reversal violating
effects with ultra-high sensitivity. In this presentation, we will not only introduce the method andits features, but also report current status of development of the polarized La target in the NOPTREX
project.

Plenary Presentations / 189

EIC accelerator
Author: Andrei Seryi11Jefferson Lab

Corresponding Author: seryi@jlab.org

The Electron-Ion Collider will be a new discovery machine for unlocking the secrets of the “glue”
that binds the building blocks of visible matter in the universe. The EIC will consist of two intersecting accelerators, one producing an intense beam of electrons (Electron Storage Ring), the othera high-energy beam of protons or heavier atomic nuclei (Hadron Storage Ring), which are steered
into collisions of spin-polarized beams in the Interaction Region. The EIC design will make use ofexisting ion sources, a pre-accelerator chain, a superconducting magnet ion storage ring, and otherinfrastructure of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The
Rapid Cycling Synchrotron will provide injection into ESR, while preserving beam polarization. The
Strong Hadron Cooling system will preserve emittances of the proton beam during collision run.
The EIC project has recently received Critical Decision 1 (CD-1) approval from DOE, and the project
team is now working on the next milestone – CD-2. The EIC project will be delivered in a collaboration of domestic and international partners. In this talk, the status of EIC accelerator will be
reviewed.

Nucleon Helicity Structure / 190

J/psi spin asymmetry measurements in p+p collisions at 200 and
510 GeV by the PHENIX experiment at RHIC
Author: alexandre lebedev1
1

Iowa State University

Corresponding Author: lebedev@iastate.edu

Studies of heavy quark bound states, like J/psi meson, provide a useful tool to investigate QCD properties. Many general features of J/psi production, such as cross-sections and transverse momentum
distributions are well described by many existing models. In order to differentiate between various
theoretical models one has to study J/psi production in more details. One of the observables which
can be used for this purpose is angular distribution of leptons produced in quarkonium decays, usually called polarization or spin asymmetry.
The PHENIX experiment at RHIC has measured inclusive J/psi polar and azimuthal angular decaycoefficients at the mid (|y|<0.35) and forward (1.2<|y|<2.2) rapidity in p+p collisions at 200 GeV andPage 81The 24th International Spin Symposium/ Book of Abstracts

510 GeV. In this talk the analysis details as well as the results in different polarization frames will bepresented and compared to theory.

Low energy spin physics with lepton, photon and hadron probes / 191

Differential cross sections and photon beam asymmetries of eta
photoproduction on the proton in the LEPS2/BGOegg experiment
Author: Toshikazu HASHIMOTO1
1

Research Center for Nuclear Physics, Osaka University

Corresponding Author: thashi@rcnp.osaka-u.ac.jp

The meson photoproduction is a useful tool to study baryon resonances.Especially, an η meson is
an isoscalar meson with ss̄ components, so it is expected to couple with N∗ states with large ss̄
components. In previous experiments, the bump structure was seen above 2 GeV in differential
cross sections of η photoproduction. But in this energy region, many resonance states exist, so it isdifficult to distinguish each contribution by just measuring the differential cross sections. Therefore,
it is necessary to measure the photon beam asymmetry, which is one of the spin observables.
The experiment was carried out in the LEPS2 beamline at SPring-8 using GeV photon beam. This
photon beam is highly linear polarized, and this polarization degree is more than 90 % in highenergy regions. Produced particles were measured using the BGOegg calorimeter and the forward
chambers. The photon beam asymmetries above 2.1 GeV were measured for the first time. We report
the experimental results and comparisons with the partial wave analysis.

Low energy spin physics with lepton, photon and hadron probes / 192

Search for the H-dibaryon near ΛΛ and Ξ− p thresholds via 12 C(K − , K + )reactions at J-PARC
Author: Shin Hyung Kim1
Co-authors: Jung Keun Ahn 1 ; Shuhei Hayakawa 2 ; Yudai Ichikawa 3
1

Korea University

2

Tohoku University

3

JAEA

Corresponding Author: fireant@korea.ac.kr

The J-PARC E42 is a dedicated experiment to search for an H-dibaryon near ΛΛ and Ξ− p threshold.
The H-dibaryon is the lightest S = −2 system which can be decomposed into a symmetric six-quark
object made from uuddss quarks and two baryon states involving ΛΛ, ΞN , and ΣΣ components. E42
detector is highlighted by a large-acceptance Superconducting Hyperon Spectrometer (SHS), whichaccommodates a GEM-based time projection chamber (HypTPC). A high-intensity K − beam wasincident on a diamond target inside the HypTPC, and outgoing K + particles were tagged using a
dipole KURAMA spectrometer. The reaction (K − , K + ) proves the production of S = −2 systems at
a beam momentum of 1.82 GeV/c. The E42 has completed physics runs in 2021. E42 data includes all
charged particles from subsequent decays in 12 C(K − , K + ) reactions. Analysis effort of the dataset is
now underway. Spin analysis of two Λs would help an experimental confirmation of the existence ofa spin-singlet H-dibaryon. We will present expected results with E42 and hadron physics programswith SHS.
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Acceleration, Storage and Polarimetry of polarized Beams / 193

The spin-injector for the P2 experiment at MESA
Authors: Kurt Aulenbacher1 ; Jennifer Groth1 ; Simon Friederich2
1

Institut für Kernphysik der Johannes Gutenberg-Universität Mainz

2

Institut für Kernphysik der Johannes Gutenberg-Unversität Mainz

Corresponding Author: aulenbac@uni-mainz.de

The P2-experiment will measure the weak charge of the proton with high precision at the MESA
accelerator facility.
Using elastic scattering of longitudinally spin polarized electrons off the proton, the parity-violating
asymmetry has to be measured with high accuracy.
New approaches have been chosen to fulfill the increased demands compared to older experiments
which to large extent concern the injection system of MESA.
These include in particular a double Wien filter for independent setting of the polarization sign andredundant polarimetry.
The beam dynamics of the spin-injector is simulated in start-to end fashion, taking space charge
effects into account.

Polarized Sources and Targets / 194

The Hydro-Moeller Polarimeter at MESA
Authors: Kurt Aulenbacher1 ; Valery Tioukine2 ; Daniel Simon3
1

Institut für Kernphysik der Universität Mainz

2

Johannes Gutenberg-Universitat Mainz, Institut fur Kernphysik

3Institut für Kernphysik der Johannes Gutenberg-Univresität Mainz

Corresponding Author: aulenbac@uni-mainz.de

A precision online polarimeter for the P2 experiment at the upcoming MESA accelerator is highly
desirable. It can be realized in the following manner: A solenoid trap is integrated into the beamline
leading towards the experiment. The trap will contain hydrogen atoms, the high magnetic field leads
to a complete electron-spin polarization. Such an arrangement allows online operation because of
low target thickness. Further, the main systematic errors of a Moeller polarimeter will be suppressed,
potentially leading to very high polarisation accuracy. We present the technical design and how thetrap and its peripheral devices can be integrated into the beamline.

Plenary Presentations / 195

Report from ISPC meeting
Corresponding Author: hgao@bnl.gov

Polarized Sources and Targets / 196

Testing a new polarized target for CLAS12 at Jefferson Lab
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Author: Christopher Keith1
1

Jefferson Lab

Corresponding Author: ckeith@jlab.org

Run Group C comprises seven experiments utilizing the CLAS12 detector system in Hall B at Jefferson Lab aiming to study the multidimensional partonic structure of nucleons. The experiments
will scatter electrons from polarized protons and neutrons in samples of solid NH3 and ND3, dynamically polarized in a 5 T magnetic field and a temperature of 1 K. After a brief description of thetarget system, the current status of the target will be presented as will results of recent tests in thelaboratory of the Jefferson Lab Target Group.

Applications of Nuclear Polarization in other Fields / 197

Nuclear Barnett effect and Nuclear Einstein-de Haas effectAuthor: Hiroyuki Chudo1
1Japan Atomic Energy Agency

Corresponding Author: chudo.hiroyuki@jaea.go.jp

Nuclear Barnett effect and Nuclear Einstein-de Haas effect
Hiroyuki Chudo1*, Mamoru Matsuo2,1,3, Sadamichi Maekawa1,2,3, and Eiji Saitoh,141Advanced Science Research Center, Japan Atomic Energy Agency, Japan
2Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, People’s Republic of China
3Riken Center for Emergent Matter Science (CEMS), Japan
4Department of Applied Physics, The University of Tokyo, Japan*chudo.hiroyuki@jaea.go.jp
Spin mechanical coupling played a crucial role in developing the quantum mechanics. The coupling
between the spin of an electron and mechanical rotation provided the first experimental proof that
an electron has an angular momentum i.e., spin by Barnett, and Einstein and de Haas in 1915 [1,2]. By using these studies, they were experimentally determined the value of the g factor of anelectron to be ~2 prior to the establishment of the modern quantum physics. The Barnett effectis the phenomenon, in which a mechanically rotating magnet is magnetized. The reverse of theBarnett effect is referred to as the Einstein- de Haas (EdH) effect, in which magnetization generates
mechanical rotation of a magnet. These effects have been studied in the electron spin system. We
have expanded these effect to the nuclear spin system. We observed the Barnett field, which is theorigin of the Barnett effect, by using coil-rotation NMR and NQR method[3, 4]. Now, we are trying
to observe the nuclear EdH effect by exploiting the dynamic nuclear polarization.
[1] S. J. Barnett, Phys. Rev. 6, 239 (1915).
[2] A. Einstein and W. J. de Haas, Deutsche Physikalische Gesellschaft 17, 152 (1915).
[3] H. Chudo, et.al., Appl. Phys. Express 7, 063007 (2014).
[4] H. Chudo, et.al., Phys. Rev. B 103, 174308 (2021).

Applications of Nuclear Polarization in other Fields / 198

Design and development of the molecular probes for applicationof the hyperpolarized-NMR/MRI
Author: Yoichi Takakusagi1

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Quantum Hyperpolarized MRI Group, Institute for Quantum Life Science, QST

Corresponding Author: takakusagi.yoichi@qst.go.jp

Hyperpolarized-nuclear magnetic resonance and imaging (HP-NMR/MRI) is a promising techniquethat allows direct monitoring of metabolic reactions in vitro and in vivo. Given the 13C- or 15Nlabeled molecular probes whose NMR signal is amplified by the dynamic nuclear polarization (DNP)
under a cryogenic magnetic field (3.35T, 1.4K), the sample is rapidly dissolved with a superheatedsolvent (~458K), and then quickly reacted with enzymes or cells, or administered in animals put into
the magnet. The metabolic reaction is readout onto the NMR spectra or MR image based on the>10,000-fold enhanced signals. By elucidating the extent of the metabolic reaction of the probes,
early detection of disease-specific elevation of enzymatic activity, metabolic reprogramming, andalteration of their flux upon the treatment is possible.
The development of various molecular probes will be a key factor to expand the utility of this approach. In this presentation, we will concisely introduce the basics of the dis-DNP, design andapplication of our recent new molecular probes that allow in vitro and in vivo HP-NMR/MRI.
1. Ardenkjær-Larsen J. H. et al. Proc. Natl. Acad. Sci. USA. 100, 10158, 2003
2. Golman K. et al. Proc. Natl. Acad. Sci. USA. 103, 11270, 2006
3. Saito K. et al. Clin. Cancer Res. 24, 3137, 2015
4. Scroggins B. T. et al. Clin. Cancer Res. 24, 3137, 2018
5. Matsumoto S. et al. Cancer Res. 78, 3783, 2018
6. Takakusagi Y. et al. Proc. ISMRM 26, 3720, 2018
7. Kondo Y. et al. Angew. Chem. Int. Ed. (Review) 60, 14779, 2021

Applications of Nuclear Polarization in other Fields / 199

Materials chemistry of triplet dynamic nuclear polarization
Author: Nobuhiro Yanai1
1

Kyushu University, JST-PRESTO

Corresponding Author: yanai@mail.cstm.kyushu-u.ac.jp

Nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) are powerful and versatile methods in modern chemistry and biology fields. Nevertheless, they suffer from
intrinsically limited sensitivity due to the low nuclear spin polarization at ambient temperature.
One of the promising methods to overcome this limitation is dynamic nuclear polarization (DNP)
that transfers spin polarization from electrons to nuclei. In particular, DNP based on photo-excitedtriplet (triplet-DNP) is promising, since it allows the hyperpolarization at room temperature. In typical scheme of triplet-DNP, the spin-selective intersystem crossing (ISC) produces the large electron
spin polarization in the excited triplet state sublevels, and this polarization is effectively transferredto nuclear spins by a pulsed microwave irradiation for satisfying Hartmann-Hahn condition, socalled integrated solid effect (ISE).
While much efforts have been devoted to obtaining the large nuclear polarization based on tripletDNP, the application of triplet-DNP has been limited to nuclear physics experiments. Towards biological applications, we have proposed to introduce materials chemistry into the field of triplet-DNP,
which realizes the hyperpolarization of nanomaterials such as nanoporous metal-organic frameworks (MOFs) and nanocrystal dispersion in water. In addition, we have developed the first examples of air-stable and water-soluble polarizing agents, which allows us to hyperpolarize crystalline
ice.

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Plenary Presentations / 200

Electron and Nuclear Spin Current Physics and Applications
Author: Eiji Saitoh1
1

Department of Applied Physics, University, Sendai, Japan

Corresponding Author: eizi@ap.t.u-tokyo.ac.jp

Spin current, a spin counterpart of electric current, refers to a flow of electrons’ and nuclear spin angular momentum in condensed matter. Spin current has been ignored in electromagnetism in matterfor many years, since it disappears in a very short distance, typically at the sub-micrometer scale.
However, recent developments in nanotechnology have enabled us to make minute structures. For
example, in integrated circuits composed of nanoscale wires, spin current may become as importanta quantity as electric current. Spin current can be detected using the inverse spin Hall effect [1]:conversion of spin current into electricity in condensed matter. As a result, a lot of spin-currentrelated phenomena have been discovered [2-6].
In my talk, I will guide you around the world of spin current science. I will give an introduction
to the basic concept of spin current, followed by a review of various phenomena discovered using
spin current as a guiding principle, such as spin-Seebeck effects[2,4] and nuclear spin Seebeck effect[5,6]. The physics and materials science behind these effects will also be discussed.
[1] E. Saitoh et al., Applied Physics letters 88 (2006) 182509.
[2] K. Uchida et al., Nature 455 778-781 (2008).
[3] Y. Kajiwara et al., Nature 464 262-266 (2010).
[4] G. E. W. Bauer et al., Nature materials 11 391-399 (2012).
[5] Y. Shiomi et al., Nature Physics 15 22-26 (2019).
[6] T. Kikkawa et al., Nature Communications 12, 4356 (2021).

Polarized Sources and Targets / 201

Status of Polarized Solid Targets in European High Energy Scattering Experiments
Author: Gerhard Reicherz1
1

Ruhr-University Bochum

Corresponding Author: gerhard.reicherz@rub.de

In Europe are running three polarized solid state targets in single and double polarized scatteringexperiments. In Bonn at ELSA and in Mainz at MAMI are two targets located. Both are so calledfrozen spin targets, which are dynamically polarized and during data taking the material is cooled
down to 50 mK and lower, where the spins are frozen what means the relaxation time is increased
to few hundred up to several thousand hours, depending on temperature and applied magnetic field.
The biggest polarized target in the world is the COMPASS target, running in the north area at CERN.
This target can run in frozen spin and in continuous wave mode depending on the physical questionof the scattering experiment.
This talk presents the status of the three experiments with a focus on the targets.

Polarized Sources and Targets / 202

Concept of projection-type 3D spin-resolving electron detector
with spatial resolution and new type of polarized electron source
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The 24th International Spin Symposium/ Book of Abstracts

Authors: Oleg Tereshchenko1 ; Vladimir A. Golyashov2 ; Vadim S. Rusetsky3 ; Andrey V. Mironov4 ; Alexander Yu.
Demin41

Institute of Semiconductor Physics, SB RAS
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090
bNovosibirsk State University, Novosibirsk 630090, Russian Federation
3
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090
4CJSC EKRAN-FEP, Novosibirsk 630060, Russian Federation
2

Corresponding Author: teresh@isp.nsc.ru

The concept of an imaging-type 3D spin detector, based on the combination of spin-exchange interactions in the ferromagnetic film and spin selectivity of the electron–photon conversion effectin a semiconductor heterostructure, is proposed and demonstrated on a model system. This novel
multichannel concept is based on the idea of direct transfer of a 2D spin-polarized electron distribution to image cathodoluminescence (CL) [1]. The detector is a hybrid structure consisting of a thinmagnetic layer deposited on a semiconductor structure allowing measurement of the spatial andpolarization-dependent CL intensity from injected spin-polarized free electrons. The ferromagnetic/
semiconductor detector has the potential for realizing multichannel 3D vectorial reconstruction ofspin polarization in momentum microscope and angle-resolved photoelectron spectroscopy systems.
A new type of spin polarized electron source based on the alkali antimonides photocathodes are
discovered. It is shown that the degree of polarization is comparable to that observed for GaAs
photocathodes.

Plenary Presentations / 203

Opening
Corresponding Author: sakurai@ribf.riken.jp

Acceleration, Storage and Polarimetry of polarized Beams / 204

Optimisation of spin-coherence time in a prototype storage ringfor electric dipole moment measurements.
Author: Rahul Shankar1
Co-authors: Max Vitz 2 ; Paolo Lenisa 1
1
2

University of Ferrara and INFN, Italy
RWTH Aachen, Forshungszentrum Jülich, Germany

Corresponding Author: shankar@fe.infn.it

The JEDI experiment is devoted to the search for the electric
dipole moment (EDM) of charged particles in a storage ring, as a very
sensitive probe of physics beyond the Standard Model. In order to reach the highest possible sensitivity, a fundamental parameter to be optimized is the particles’ Spin Coherence Time (SCT), i.e., thetime interval within which the particles of the stored beam maintain a net polarization greater than
1/e. To identify the working conditions that maximize SCT, accurate spin-dynamics simulations
with the code BMAD have been performed on the lattice of a “prototype” storage ring which uses
a combination of electric and magnetic fields for bending. The talk will present the results of thesesimulations addressing the impact on the SCT of different factors like horizontal tune, synchrotron
tune and effect of the electric bending components.

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