bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of shadowing and antishadowing corrections to the evolution of gluon density at small-x
Authors: Devee Mayuri
Published: March 2020

We have obtained a semi-analytical solution of GLR-MQ-ZRS equation at small x for gluon density using Regge like ansatz of G(x,Q
2) in the leading twist approximation. It is observed that, our solution is valid in the vicinity of saturation scale where modification in the QCD evolution can not be ruled out due to salient gluon fusion processes. Our computed results of nonlinear gluon density are then compared with different global parameterizations and it is enticing to note that, the rapid growth of gluon densities towards small-x is tamed due to the nonlinear corrections.
Search for triple and quadruple beta decay of 150Nd using low-background HPGe detector
Authors: Barabash A.S. , Hubert Ph. , Nachab A. , Umatov V.I.
Published: March 2020

Triple beta decay of 150Nd to the ground and excited states of 150Eu and quadruple beta decay of 150Nd to the excited states of 150Gd have been studied using a 400 cm3 low-background HPGe detector. A half-life limit for the quadruple beta decay to the

0
1
+

state of 150Gd was found to be T1/2(0v + 4v) > 8.7 × 1020 yr (90% C.L.). For other (0v+4v) transitions to the excited states limits for the first time have been obtained at the level of (6.1 − 9.5) × 1020 yr (90% C.L.). We report here also the results for the first search for triple beta decay to the ground and excited final states of 150Eu, T
1/2(0v + 3v) > (0.04 − 4.8) × 1020 yr (90% C.L.).
The NEXT experiment for neutrinoless double beta decay searches
Authors: Benlloch-Rodriguez Jose M.
Published: March 2020

NEXT is an experiment to search for the neutrinoless double beta decay of 136Xe using a high pressure xenon gas time projection chamber. This detector technology has several key advantages, including excellent energy resolution, powerful event classification based on track topology, and favorable mass scalability. The current stage of the experiment, NEXT-White, has been taking data at the Canfranc Underground Laboratory (LSC) in Spain since late 2016. In this talk, we will review recent results from NEXT-White after the first year of low-background operations with both 136Xe-depleted and 136Xe-enriched xenon gas. Background measurements will be shown as well as preliminary results on the two-neutrino mode double beta decay.
Development of signal readout electronics for LEGEND-1000
Authors: Edzards Frank , Mertens Susanne , Willers Michael
Published: March 2020

The Large Enriched Germanium Experiment for Neutrinoless ββ Decay (LEGEND) is a future ton-scale experimental program that will search for neutrinoless double beta decay (0vββ) in the isotope 76Ge with an unprecedented sensitivity. To achieve the projected discovery sensitivity at a half-life beyond 1028 yr after about ten years of data taking, it is of utmost importance to operate in a background-free environment. This can be supported by using highly integrated readout electronics such as application-specific integrated circuit (ASIC) technology. In this work we investigated the properties and electronic performance of a commercially available ASIC charge sensitive preamplifier, the XGLab CUBE preamplifier, together with a p-type point contact high-purity germanium detector.
Results of the MAJORANA DEMONSTRATOR’s Search for Double-Beta Decay of 76Ge to Excited States of 76Se
Authors: Guinn I.S. , Arnquist I.J. , Avignone F.T. , Barabash A.S. , Barton C. J. , Bertrand F.E. , Bos B. , Busch M. , Buuck M. , Caldwell T.S. , Chan Y-D. , Christofferson C.D. , Chu P-H. , Clark M.L. , Cuesta C. , Detwiler J.A. , Drobizhev A. , Edwins D. W. , Efremenko Yu. , Ejiri H. , Elliott S.R. , Gilliss T. , Giovanetti G.K. , Green M.P. , Gruszko J. , Guiseppe V.E. , Haufe C.R. , Hegedus R.J. , Henning R. , Hervas Aguilar D. , Hoppe E.W. , Hostiuc A. , Kidd M.F. , Kim I. , Kouzes R.T. , Lopez A.M. , López-Castaño J.M. , Martin E. L. , Martin R.D. , Massarczyk R. , Meijer S.J. , Mertens S. , Myslik J. , Oli T.K. , Othman G. , Pettus W. , Poon A.W.P. , Radford D.C. , Rager J. , Reine A.L. , Rielage K. , Ruof N.W. , Stortini M.J. , Tedeschi D. , Varner R.L. , Wilkerson J.F. , Wiseman C. , Xu W. , Yu C.-H. , Zhu B.X.
Published: March 2020

The MAJORANA DEMONSTRATOR is searching for double-beta decay of 76Ge to excited states (E.S.) in 76Se using a modular array of high purity Germanium detectors. 76Ge can decay into three E.S.s of 76Se. The E.S. decays have a clear event signature consisting of a ββ-decay with the prompt emission of one or two γ-rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of (0.56 ‒ 2.1) ⋅ 1024 y. In particular, for the 2v transition to the first 0+ E.S. of 76Se, a lower half-life limit of 0.68 ⋅ 1024 at 90% CL was achieved.
Neutrino CP Violation with the European Spallation Source neutrino Super Beam project
Authors: Gramstad Eirik
Published: March 2020

After measuring in 2012 a relatively large value of the neutrino mixing angle θ
13, the door is now open to observe for the first time a possible CP violation in the leptonic sector. The measured value of θ
13 also privileges the 2nd oscillation maximum for the discovery of CP violation instead of the usually used 1st oscillation maximum. The sensitivity at this 2nd oscillation maximum is about three times higher than for the 1st oscillation maximum inducing a lower influence of systematic errors. Going to the 2nd oscillation maximum necessitates a very intense neutrino beam with the appropriate energy. The world’s most intense pulsed spallation neutron source, the European Spallation Source (ESS), will have a proton linac with 5 MW power and 2 GeV energy. This linac, under construction, also has the potential to become the proton driver of the world’s most intense neutrino beam with very high potential to discover a neutrino CP violation. The physics performance of that neutrino Super Beam in conjunction with a megaton underground Water Cherenkov neutrino detector installed at a distance of about 500 km from ESS has been evaluated. In addition, the choice of such detector will extent the physics program to proton–decay, atmospheric neutrinos and astrophysics searches. The ESS proton linac upgrades, the accumulator ring needed for proton pulse compression, the target station optimization and the physics potential are described. In addition to neutrinos, this facility will also produce at the same time a copious number of muons which could be used by a muon collider. The ESS neutron facility will be fully ready by 2023 at which moment the upgrades for the neutrino facility could start.
New Physics with Scalar and Dark Non-Standard Interactions in Neutrino Oscillation
Authors: Ge Shao-Feng
Published: March 2020

The neutrino oscillation can arise from not just the genuine neutrino mass term but also neutrino non-standard interactions with the environmental matter or dark matter (DM). It is true that neutrino oscillation indicates some new physics beyond the Standard Model, but it is not necessarily a genuine neutrino mass term. We point out two possibilities of the scalar or dark non-standard interactions (NSI), both of which can induce correction to the neutrino mass term in the effective Hamiltonian that describes neutrino oscillation and hence opens the possibility of faking the neutrino mass term.
Collective flavor conversion including the neutrino halo in core-collapse supernovae
Authors: Zaizen Masamichi , Cherry John F. , Takiwaki Tomoya , Horiuchi Shunsaku , Kotake Kei , Umeda Hideyuki , Yoshida Takashi
Published: March 2020

We investigate collective neutrino oscillation (CNO) including neutrino halo effects in an iron core-collapse supernova model. We find that CNO suddenly occurs beyond the propagating shock front evolved from a 9.6M
⊙ star. Also, we find that neutrinos inwardly scattered by background matter can be ignored outside the shock front where CNO can occur, compared with outward-going neutrinos. Neutrinos get free from matter suppression and scattering with background matter beyond the shock front. Neutrino halo with wider intersection angles produces additional flavor transformation and sharpens the spectral splits.
Liquid Xenon detector R&D for 0v2ß search (KamXP)
Authors: Ueshima Kota
Published: March 2020

The R&D for a new type of liquid xenon (LXe) detector is ongoing to search for the neutrinoless double-beta decay (0v2β). As a result of the KamLAND-Zen experiment, it is very important to realize the all active region detector for the energy deposition of the radiation. Newly developed additional BG reduction techniques will improve the sensitivity of 0v2β search in the future. Our detector concept is LXe stored in a new type of plastic scintillator vessel. The wavelength of LXe scintillation light is shifted to visible light from 175nm (VUV) on the inner surface of the vessel. Therefore, the LXe scintillation light can be detected by photon sensors which are far away from the 0v2β target nuclei. The pulse shape difference between LXe and plastic scintillator is used for the additional BG reduction. In the future, 8B solar neutrino events will be one of the dominant BGs in 0v2β search. To reduce the 8B solar neutrino BG, the directional information of the Cherenkov light might be useful. The status of LXe detector R&D to improve the sensitivity of 0v2β search is reported.
ZICOS - Neutrinoless Double Beta Decay experiment using Zr-96 with an organic liquid scintillator -
Authors: Fukuda Yoshiyuki , Moriyama Shigetaka , Hiraide Katsuki , Ogawa Izumi , Gunji Takahiro , Hayami Ryohei , Tsukadaw Satoru , Kurosawa Shunsuke
Published: March 2020

A liquid scintillator containing a tetrakis(isopropyl acetoacetato)zirconium has been developed for ZICOS experiment. In order to reach the sensitivity

T

1
/
2

0
v

≥

10

27

years, we have to use tone scale of 96Zr and have to reduce 95 % of backgrounds from 208Tl decay, which should be major backgrounds observed around Q-value (3.35 MeV) of 96 Zr neutrinoless double beta decay. According to the Monte Carlo simulation, we demonstrated that new method using the topological information of Cherenkov light could reduce 93 % of 208Tl background with 78 % efficiency for 0vββ signal. For an identification of Cherenkov light, the precise spectral pulse shape from both Cherenkov and scintillation was directly measured by using sub-MeV electrons from 90Sr/90Y beta source. The observed pulse rise and fall (decay) time for Cherenkov light were 0.8 ns and 2.5 ns, respectively. They were actually shorter than those times of scintillation light which were also measured by 1.6 ns and 6.5 ns, respectively. This clear difference of rise time will be used for the pulse shape discrimination in order to select photomultiplier tube which receives Cherenkov lights, and the topological information of Cherenkov light will be used for the reduction of backgrounds from 208Tl decay.
Neutrino evolution and quantum decoherence
Authors: Stankevich Konstantin , Studenikin Alexander
Published: March 2020

Neutrino interactions with an external environment can influence the neutrino oscillation pattern and the oscillations can be damped as a result of the neutrino quantum decoherence. In particular, the quantum decoherence of neutrino states engendered by the neutrino radiative decay accounting for the nonstandard interactions (NSI) leads to the suppression of flavor neutrino oscillations in the solar neutrino fluxes.
Coherency in Neutrino-Nucleus Elastic Scattering
Authors: Sharma V. , Wong H. T.
Published: March 2020

Elastic scattering of neutrino with nucleus (v Ael
) is the well defined weak interaction processes in the Standard Model. The TEXONO collaboration adopt electro-cooled point contact Germanium detector technology with sub-keV sensitivities for the detection of v Ael
with reactor neutrinos. The detection of v Ael
cross-section is beneficial in studies of irreducible background in dark matter experiments, study of Solar and Supernova processes, etc. It also provides the probe the quantum mechanical coherence effects in electroweak interactions. We defined a parameter α to measure degree of coherency in v Ael
. Reactor neutrinos are found to be one of the best candidates to probe v Ael
with high coherency. The divergence from full coherence leads to the study of neutron density distribution and to constrain the sensitivities in probing physics beyond the Standard Model.
Expanding Core-Collapse Supernova Search Horizon of Neutrino Detectors
Authors: Halim Odysse , Vigorito C , Casentini C , Pagliaroli G , Drago M , Fafone V
Published: March 2020

Core-Collapse Supernovae, failed supernovae and quark novae are expected to release an energy of few 1053 ergs through MeV neutrinos and a network of detectors is operative to look online for these events. However, when the source distance increases and/or the average energy of emitted neutrinos decreases, the signal statistics drops and the identification of these low statistic astrophysical bursts could be challenging. In a standard search, neutrino detectors characterise the observed clusters of events with a parameter called multiplicity, i.e. the number of collected events in a fixed time-window. We discuss a new parameter called ξ (=multiplicity/duration of the cluster) in order to add the information on the temporal behaviour of the expected signal with respect to background. By adding this parameter to the multiplicity we optimise the search of astrophysical bursts and we increase their detection horizon. Moreover, the use of the ξ can be easily implemented in an online system and can apply also to a network of detectors like SNEWS. For these reasons this work is relevant in the multi-messengers era when fast alerts with high significance are mandatory.
Constraints on Nonstandard Neutrino Interaction from Neutrino Electron Scattering
Authors: Deniz M , Wong H T
Published: March 2020

Neutrino-electron scattering is a purely leptonic fundamental interaction and therefore provides an important channel to test the Standard Model (SM), especially at the low energy-momentum transfer regime [1, 2]. In this study Data on

v
¯

e

−
e

and ve
− e scattering from the TEXONO and LSND experiments, respectively, are used and constraints on neutrino Non-Stardard-Interactions (NSI) couplings depending on model-independent approaches, which are described by a four-Fermi point like interaction and depending on several beyond-Standard-Model-physics scenarios, mediated by massive intermediate particles including (1) an extra Z-prime gauge boson, (2) a new light spin-1 boson (NLS1B), (3) Dark Photon (DP), and (4) a charged Higgs boson (CHB), are placed via the neutrino-electron scattering channel to test the SM at a low energy-momentum transfer regime. The relevant parameter spaces are extended by allowing light mediators.
38 years of galactic observations in searching for neutrino bursts from core collapse supernovae with the Baksan Underground Scintillation Telescope
Authors: Petkov V B , Boliev M M , Dzaparova I M , Kochkarov M M , Kurenya A N , Novoseltsev Yu F , Novoseltseva R V , Striganov P S , Yanin A F
Published: March 2020

The core collapse of a massive star in the Milky Way will produce a neutrino burst, which will be detected by the Baksan Underground Scintillation Telescope (BUST). The stable and enough low background at the BUST is a clear asset for searching for neutrino bursts. Now two parts of the facility (with the total mass of 242 tons) are used as independent coinciding detectors. Such approach allows us to increase dependability detection of the neutrino signal and the radius of sensitivity of the BUST. The facility has the potential to see a supernova in the Galaxy independently from other detectors.

No burst candidate for the core collapse has been detected during the observation period of June 30, 1980, to June 30, 2019. The actual observation time is 33.477 years. This is the longest observation time of our Galaxy with neutrinos at the same facility. An upper bound on the mean frequency of gravitational collapses in the Galaxy is 6.88 per century (at 90% C.L.).
New ideas for ring formation and reconstruction in water-Cherenkov detectors
Authors: Berns Lukas
Published: March 2020

Water-Cherenkov detector technology is well established as is easily seen in the almost identical designs of Kamiokande, Super- and Hyper-Kamiokande. We explore methods to further improve upon their success by extracting directional information from originally lost photons using reflectors placed in the inactive space between PMTs. The reflected photons form a secondary antipodal ring, sensitive to the vertex position and track topology. We further show how ring reconstruction algorithms can benefit from modeling variations of the Cherenkov profile due to showering. Monte Carlo based quantitative estimates are accompanied by discussions of strategies to overcome potential issues with the presented methods. A new CNN-architecture to efficiently implement the cylindrical topology and geometry is also presented.
Angular power spectrum analysis on current and future high-energy neutrino data
Authors: Dekker Ariane , Chianese Marco , Ando Shin’ichiro
Published: March 2020

To constrain the contribution of source populations to the observed neutrino sky, we consider isotropic and anisotropic components of the diffuse neutrino data. We simulate through-going muon neutrino events by applying statistical distributions for the fluxes of extragalactic sources and investigate the sensitivities of current (IceCube) and future (IceCube-Gen2 and KM3NeT) experiments. The angular power spectrum is a powerful probe to assess the angular characteristics of neutrino data and we can already constrain rare and bright sources with current IceCube data. In addition, decaying and annihilating very heavy dark matter is a potential neutrino source, as suggested by the observed excess in the High-Energy Starting Event dataset. We apply an angular power spectrum analysis to HESE data for different dark matter models, allowing us to interpret the observed neutrino sky and perform a sensitivity forecast.
Modular invariance approach to masses and mixing of neutrino flavors
Authors: Tanimoto Morimitsu
Published: March 2020

We discuss the phenomenological implications of the modular symmetry Γ(3) ≃ A
4 of lepton flavors. The mass matrices of neutrinos and charged leptons are given by fixing the modulus τ, which is the only source of the breaking of the modular invariance.
Relic neutrino clustering in the Milky Way
Authors: de Salas Pablo F.
Published: March 2020

The Standard Cosmological Model predicts the existence of relic neutrinos, which are indirectly probed through the effective number of relativistic species in the early Universe. In addition, from neutrino flavour oscillations we know that at least two of the neutrino mass states have a non-zero mass. Since the expansion of the Universe has diluted the energy of relic neutrinos, those that are massive are also non relativistic today. This means that they can be trapped in strong gravitational potentials, such as the one of the Milky Way. We review the calculation of the local overdensity of relic neutrinos produced from the gravitational attraction of our Galaxy, Andromeda and the Virgo cluster, commenting on the implications for an experiment aiming at relic neutrino detection, such as the PTOLEMY project.
Pre-supernova neutrino emission from massive stars and their detection
Authors: Kato Chinami , Nagakura Hiroki , Furusawa Shun , Takahashi Koh , Umeda Hideyuki , Yoshida Takashi , Ishidoshiro Koji , Yamada Shoichi
Published: March 2020

Recent progress of neutrino detectors makes it possible to detect pre-SN neutrinos, which are emitted from the core of massive stars before supernova explosions. Pre-SN neutrino observations will become an alarm for supernovae. We hence calculate the number luminosity and energy spectra of pre-SN neutrinos from the 15 M
⊙ progenitor based on the state-of-the-art calculations of massive stars. We find that the number luminosity of ve
’s is

L
N
v

∼

10

55

,

10

57

s

−
1

before core collapse and core bounce, respectively, whereas that of

v
¯

e

’s becomes largest around core collapse

L
N
v

∼

10

53

s

−
1

. We then estimate the number of neutrino events at neutrino detectors taking neutrino oscillations into the obtained luminosities and spectra. We find that an alarm is issued a few days before the explosion by detecting

v
¯

e

’s at liquid-scintilation type detectors if the progenitor is located at 200 pc. Finally, we perform a systematic study of pre-SN neutrino emission for 7 progenitor models with different initial masses. We find that the difference of the number luminosities is ~ 1 order and the dependence of the initial mass have to be taken into the theoretical predictions of pre-SN neutrino observations.
Entropy production from decay of GeV scale right-handed neutrinos and the primordial gravitational wave
Authors: Okui Hisashi
Published: March 2020

Right-handed neutrinos are attractive particles beyond the standard model introduced in the seesaw mechanism [1] that can explain tiny neutrino masses. We revisit the entropy production from the decay of right-handed neutrinos with GeV scale masses. This additional entropy production dilutes the dark matter and baryon abundances. Furthermore, we point out that it gives the effect on the primordial gravitational wave spectrum. Primordial gravitational waves are closely related to the thermal history of the universe, and then the modified history by right-handed neutrino is imprinted in the gravitational wave spectrum12.
Statistical methods in sterile neutrino experiments
Authors: Neumair Birgit , Agostini Matteo
Published: March 2020

We compare the current statistical methods applied to short-baseline neutrino oscillation experiments looking for light sterile neutrinos. The interpretation of the reconstructed confidence regions differs because of the different definition of the alternative hypothesis in the hypothesis test. When the alternative hypothesis extends over the whole physical allowed parameter space of the oscillation parameters, proper confidence regions are obtained both in case of a limit and a signal. Since the different definition of the alternative hypothesis prevents from a direct comparison of the results, a standardized analysis is proposed.
Hunting keV sterile neutrinos with KATRIN: building the first TRISTAN module
Authors: Houdy T , Alborini A , Altenmüller K , Biassoni M , Bombelli L , Brunst T , Carminati M , Descher M , Fink D , Fiorini C , Gugiatti M , Huber A , King P , Korzeczek M , Lebert M , Lechner P , Mertens S , Pavan M , Pozzi S , Radford D C , Sedlak A , Siegmann D , Urban K , Wolf J
Published: March 2020

The KATRIN (Karlsruhe Tritium Neutrino) experiment investigates the energetic endpoint of the tritium beta-decay spectrum to determine the effective mass of the electron anti-neutrino. The collaboration has reported a first mass measurement result at this TAUP-2019 conference. The TRISTAN project aims at detecting a keV-sterile neutrino signature by measuring the entire tritium beta-decay spectrum with an upgraded KATRIN system. One of the greatest challenges is to handle the high signal rates generated by the strong activity of the KATRIN tritium source while maintaining a good energy resolution. Therefore, a novel multi-pixel silicon drift detector and read-out system are being designed to handle rates of about 100 Mcps with an energy resolution better than 300 eV (FWHM). This report presents succinctly the KATRIN experiment, the TRISTAN project, then the results of the first 7-pixels prototype measurement campaign and finally describes the construction of the first TRISTAN module composed of 166 SDD-pixels as well as its implementation in KATRIN experiment.
Analysis strategies and treatment of systematic effects in the KATRIN experiment
Authors: Slezák Martin
Published: March 2020

The Karlsruhe Tritium Neutrino (KATRIN) experiment aims to search for the effective electron antineutrino mass with a sensitivity of 0.2 eV/c2 (90% C.L.) from the shape of the tritium β-decay electron energy spectrum. The first measurement campaign in KATRIN dedicated to the neutrino mass took place in spring 2019 with about 22 % of the nominal tritium activity. The goal of this pilot measurement was to reach a sensitivity competitive with past results while establishing a robust bias-free analysis and good initial understanding of systematic effects. Several different analysis techniques were developed independently and cross-checked on a set of fake Monte Carlo prior to real spectra. In this paper, I present an overview of the KATRIN analysis strategies and discuss their applications on the tritium spectra. The treatment of systematic effects is also discussed in detail. I conclude with a short outlook for the future neutrino mass measurement campaigns with KATRIN.
NEOS: reactor neutrino experiment at short baseline
Authors: Oh Yoomin
Published: March 2020

Numbers of experiments are trying to measure an active-to-sterile neutrino oscillation using nuclear reactors. A precise measurement of the energy spectrum is also important to understand the reactor neutrinos and for their applications. The NEOS experiment is being conducted at 24 meter distance from a 2.8 gigawatt thermal power nuclear reactor core. It aims at finding a short baseline oscillation due to an eV scale sterile neutrino, and to provide a reactor neutrino energy spectrum with a high resolution and a high signal-to-background ratio.
Sum rules and asymptotic behaviors of neutrino mixing and oscillations in matter
Authors: Xing Zhi-zhong , Zhu Jing-yu
Published: March 2020

Similar to the case in vacuum, it is straightforward to describe neutrino oscillations in matter with the effective lepton flavor mixing matrix

U
∼

and neutrino mass-squared differences

Δ
∼

j
i

≡

m
∼

j
2

−

m
∼

i
2

(i, j = 1, 2, 3). By calculating two sets of sum rules of

U
∼

and

Δ
∼

j
i

, we have derived exact expressions of

|

U
∼

α
i

|

2

and

U
∼

α
i

U
∼

β
i

*

(for α, β = e, μ, τ and i = 1, 2, 3) and discussed the asymptotic behaviors of

|

U
∼

α
i

|

2

and

U
∼

and

Δ
∼

j
i

in very dense matter (i.e., in the limit of the matter parameter

A
=
2

2

G
F

N
e

E

approaching infinity).
Progress of Veto Detector of JUNO
Authors: Zhang Peng
Published: March 2020

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kiloton liquid scintillator detector with neutrino mass hierarchy determination as primary physics goal. The other measurements, including precise neutrino oscillation parameters, solar neutrino, geo-neutrino, supernova neutrinos and the diffuse supernova neutrinos background, will be performed at the same time. The detector will be built in a 700 meter deep underground laboratory. A multi-eto detector, composed of a Top Tracker and a Water Cherenkov, will be installed for cosmic muon detection and background reduction. The Top Tracker detector is placed above the central detector, and is composed of three layers of scintillating strips. The outer part of the Central Detector is filled with water and equipped with about 2400 MCP-PMTs (20 inches) to form the Water Cherenkov detector used for muon tagging. Thanks to the Veto detector, the cosmic muon induced fast neutron background can be reduced to a level of about 0.06/day.
Accuracy improvement of the atmospheric neutrino flux prediction using observed muon spectra at mountain altitude
Authors: Honda Morihiro , Sajjad Athar M. , Kajita Takaaki , Kasahara Katsuaki , Midorikawa Shoichi , Nishimura Jun
Published: March 2020

By the study of the variations of the atmospheric neutrino and muon fluxes, due to that of the hadronic interaction, we find that when have accurate atmospheric muon flux data, we can estimate the prediction error of the atmospheric neutrino flux calculating with the same interaction model from the residual. However, the relation of the residual of the muon flux and the error in the neutrino flux is largely dependent on the observation site of the muon flux. We study this relation at several observation sites, near Kamioka at sea level, same but 2770m a.s.l.., Hanle India (4500m a.s.l.), and at Balloon altitude (~ 32km).
Phenomenological study of texture zeros of neutrino mass matrix in minimal left-right symmetric model
Authors: Borgohain Happy , Das Mrinal Kumar , Borah Debasish
Published: March 2020

We studied the phenomenological implications of texture zeros in the neutrino mass matrix of the minimal left-right symmetric model (LRSM). Since the possibility of maximum zeros reduces the maximum number of free parameters of the model making it more predictive, we considered only those cases with maximum possible texture zeros in light neutrino mass matrix Mv
, Dirac neutrino mass matrix MD
and heavy right-handed (RH) neutrino mass matrix MRR
. We then computed the correlations among the different light neutrino parameters and then the new physics contributions to neutrinoless double beta decay(NDBD) for the different texture zero cases. We find that for RH neutrino masses above 1 GeV, the new physics contributions to NDBD can saturate the corresponding experimental bound.
TRISTAN measurements at the Troitsk nu-mass experiment
Authors: Brunst Tim
Published: March 2020

The KATRIN (Karlsruhe Tritium Neutrino) experiment investigates the energetic endpoint of the tritium beta-decay spectrum to determine the effective mass of the electron anti-neutrino with a sensitivity of 200 meV (90 % C.L.) after an effective data taking time of three years. The TRISTAN (tritium beta-decay to search for sterile neutrinos) group aims at detecting a sterile neutrino signature by measuring the entire tritium beta-decay spectrum with an upgraded KATRIN system. One of the greatest challenges is to handle the high signal rates generated by the strong activity of the KATRIN tritium source. Therefore, a novel multipixel silicon drift detector is being designed which is able to handle rates up to 100 Mcps with an excellent energy resolution for electrons of 300 eV (FWHM) at 10 keV. First seven-pixel prototype detectors were successfully installed and operated at the Troitsk nu-mass experiment, one of KATRIN’s technological predecessors. In this work, we present the results of these measurement campaigns.
Electromagnetic neutrinos: New constraints and new effects in oscillations
Authors: Studenikin Alexander
Published: March 2020

A short overview of neutrino electromagnetic properties with focus on existed experimental constraints and future prospects is presented. The related new effect in neutrino flavour and spin-flavour oscillations in the transversal matter currents is introduced.
The laser Isotope separation (LIS) methods for the enrichment of 48Ca.
Authors: Matsuoka K , Niki H , Ogawa I , Shinki Y , Kawashima Y , Matsumura K
Published: March 2020

Neutrino-less double beta decay measurement is a powerful tool to test the Majorana nature of neutrinos. Among the potential double beta decay nuclei, 48Ca has the largest Q value (4.3 MeV), we can expect the least background measurement. On the other hand, a smallness of natural abundance of 48Ca (~0.2%) requires an enrichment to increase the sensitivity to reach interesting regions (Inverted Hierarchy and Normal Hierarchy). We have been studying the laser isotope separation (LIS) methods for the enrichment of 48Ca, where a narrow band diode laser is used to excite the specific isotope in the calcium vapor beam. For the separation, two methods (deflection and ionization) are employed. In the deflection method, the 48Ca atoms are deflected by momentum transfers from laser photons by multiple absorption and emission. In the ionization method, an additional dye laser is used to ionize the excited 48Ca. In this paper, we will report the current status and future prospects of two methods of LIS for the enrichment of 48Ca.
Impact of theoretical reactor flux uncertainties and of the near detector on the JUNO measurements
Authors: Marrone Antonio , Capozzi Francesco , Lisi Eligio
Published: March 2020

JUNO is medium-baseline reactor neutrino experiment that will probe the neutrino spectrum mass ordering (MO) and will measure the mass-mixing oscillation parameters with unprecedented sub-percent precision. It will be complemented with a ton-level, high energy resolution liquid scintillator reference detector, TAO, that will measure the reactor neutrino spectrum with unprecedented accuracy. In this work we study if the limited knowledge of the reactor antineutrino spectrum and of its fine structure can have a significant effect on the mass ordering determination and on the precision measurements of the oscillation parameters, and try to assess the advantages of having the TAO reference detector.
Sensitivity to leptonic CP violation at Hyper-Kamiokande
Authors: Boschi T.
Published: March 2020

Hyper-Kamiokande is a next generation water Clierenkov detector, an order of magnitude larger than Super-Kamiokande. capable of large and diverse physics studies. Among these, it will study long baseline oscillation physics with great detail, thanks not only to a larger volume and higher detection efficiency, but also to an improved accelerator and near detector system at J-PARC. We study the effect of a new systematic error model 011 the overall sensitivity of the experiment to the neutrino oscillation parameters, with particular care for the CP violating phase. A variety of theoretical models will benefit from a precise measurement of δ
CP, which Hyper-Kamiokande has the capability of constraining, with good precision. The accuracy of the measurement, however, is dictated by the systematic uncertainties and hence it is essential to assess the impact of the new error model 011 the sensitivity.
Detector Physics with MicroBooNE
Authors: Chen Yifan
Published: March 2020

The MicroBooNE detector is a liquid argon time projection chamber (LArTPC), designed for the short-baseline neutrino physics program in the Booster neutrino beamline at Fermilab. Because of their exceptional calorimetric and tracking capabilities, LArTPCs are employed in many current and future neutrino experiments. MicroBooNE, as an operating physics experiment, plays a crucial role in characterising the performance of this technology. We present an overview of the ongoing detector physics studies in MicroBooNE, including a brief introduction to the detector sub-systems and a procedure for calibrating calorimetry in LArTPC. The latter involves studies of signal processing, charge uniformity, ionised electron lifetime and charge recombination. Through the laser system in MicroBooNE, we demonstrate that profound knowledge of the electric field is essential to conduct a neutrino experiment with LArTPCs.
Measuring the coherent elastic neutrino-nucleus scattering with an high intensity 51Cr radioactive source
Authors: Di Noto L , Bellenghi C , Chiesa D , Pallavicini M , Previtali E , Vignati M
Published: March 2020

The idea of measuring the coherent elastic nuclear scattering of neutrinos emitted by a high intensity 51Cr radioactive source is investigated. To produce the high intensity source, the radioactive material used in the GALLEX experiment (36 kg of Chromium 38.6% enriched in 50Cr) could be reactivated to an intensity of few MCi. The advantages of this source are that the activity can be measured at few per mill level and that the neutrino spectrum is well known. With a target volume of 2 dm3 of low-threshold detectors, if the background is limited, the crosssection might be measured with few percent precision. In this work the requirements for the experiment will be shown and the envisioned experimental challenges will also be discussed.
No tension between pulsar timing array upper limits on the nano-Hertz gravitational wave background and assembly models of massive black hole binaries
Authors: Middleton Hannah , Chen Siyuan , Pozzo Walter Del , Sesana Alberto , Vecchio Alberto
Published: March 2020

Pulsar timing arrays provide a means to observe the nano-Hertz gravitational wave background from the population of merging massive black hole binaries. Observations are placing increasingly stringent upper limits on the gravitational wave background. Upper limits and future detections will enable the study of the properties of the merging population. Recent upper limits have cast doubt on current predictions of the gravitational wave background. Here we perform a Bayesian analysis comparing upper limits to astrophysical prediction. So far models are consistent with observation. These proceedings summarise previous work in Ref. [1].
Prompt and accurate sky localization of gravitational-wave sources
Authors: Morisaki Soichiro , Raymond Vivien
Published: March 2020

Accurate, precise and prompt sky localization of gravitational-wave sources is essential to the success of multi-messenger astronomy. One of the most accurate sky localizations we can obtain is from full signal parameter estimation obtained with the LIGO-Virgo LALInference software, done after a quick initial sky localization with the Bayestar software. While more accurate, the improved analysis can take on the order of months to complete for a binary neutron star event. To solve this issue, we develop a new technique to speed up the parameter estimation. Our technique speeds up the parameter estimation by a factor of

O

(104) and enables updating the sky localization within 10 minutes after the detection.
Formation of binary black holes in star clusters as gravitational wave sources
Authors: Kumamoto Jun , Fujii Michiko S. , Tanikawa Ataru
Published: March 2020

Direct detections of gravitational wave suggest that ~ 30 solar mass binary black holes (BBHs) commonly exist in the Universe. One possible formation scenario of such BBHs is dynamical three-body encounters in a dense core of globular clusters, which consist of millions of stars. Compared to globular clusters, open clusters are less dense and less massive but more populous. Because of their shallow potential, they have not been considered to be a formation site of merging BBHs. However, we found a new channel for the formation of BBHs, which is dominant in open clusters. We performed direct N-body simulations of open clusters with a mass of 2500 solar mass for metallicity of Z/Z
⊙ = 0.1. The core-collapse time of open clusters is much shorter than that of globular clusters. Therefore, massive main-sequence stars can form binaries before they evolve to BHs. These main-sequence binaries experience mass transfer evolution, and some of them evolve to BBHs merging within the Hubble time. From our simulations, we estimated the merger rates of BBHs originated from open clusters.
Use of poly(ethylene naphthalate) as a self-vetoing structural material
Authors: Efremenko Y , Fajt L , Febbraro M , Fischer F , Guitart M , Hackett B , Hayward C , Hodák R , Majorovits B , Manzanillas L , Muenstermann D , Öz E , Pjatkan R , Pohl M , Radford D , Rouhana R , Schulz O , Štekl I , Stommel M
Published: March 2020

Poly(ethylene naphthalate), PEN, is an industrial polyester which has been shown to scintillate in the blue wavelength region. Combined with measurements of a high intrinsic radiopurity, this has sparked interest in the material for use in low-background experiments.
Cryogenic Electronics Development for CUPID
Authors: Huang R G , Mei Y , Kolomensky Yu G , Grace C
Published: March 2020

CUPID (CUORE Upgrade with Particle ID) is a next-generation ton-scale bolometric experiment that will search for neutrinoless double beta decay. CUPID will have reduced backgrounds compared to CUORE through the ability to distinguish between 0vββ events and α backgrounds by detecting light emissions. To achieve this, it will deploy on the order of 3000 sensors in its detector array, which will introduce additional technical challenges compared to the 1000 sensors currently in CUORE. Using only room-temperature electronics for CUPID would increase the thermal load on the cryostat from the necessary cabling and increase the complexity of the vacuum system. A multiplexed readout with cryogenic electronics is a potentially appealing solution to these challenges. This work will present a characterization of CMOS devices that will guide future cryogenic ASIC design for CUPID readout.
Development and performance of the 20” PMT for Hyper-Kamiokande
Authors: Bronner C , Nishimura Y , Xia J. , Tashiro T.
Published: March 2020

The inner detector of the future Hyper-Kamiokande experiment will be instrumented with 40000 20” photo-multiplier tubes (PMTs). Two models of PMTs are considered: the R12860 from Hamamatsu Photonics (nominal option), and the GDB-6203 from North Night Vision Technology (alternative option). Both models show improved performances compared to the PMTs used in the currently running Super-Kamiokande experiment. We present here the measurements of the performance of the nominal and alternative option PMTs done in the context of the Hyper-Kamiokande project, as well as the first use of those new PMTs in a running experiment, and other on-going developments for their future use in the Hyper-Kamiokande detector.
Characterization of new photo-detectors for the future dark matter experiments with liquid xenon
Authors: Ozaki Kosuke , Kazama Shingo , Yamashita Masaki , Itow Yoshitaka , Moriyama Shigetaka
Published: March 2020

In the last three decades, numerous terrestrial experiments were built to search for a faint interaction between Weakly Interacting Massive Particles (WIMP) and ordinary matter. Among them, experiments using dual-phase xenon time projection chambers (TPCs) are leading the search especially for high mass WIMPs. In these experiments, photomultipliers (PMTs) are used to detect the prompt primary scintillation and secondary electro-luminescence of ionized electrons generated following an interaction between WIMP and a Xe nucleus. However, PMTs have several important shortcomings: their residual radioactivity levels, cost, bulkiness, and stability at cryogenic temperatures. Therefore, several alternative technologies are under consideration toward future dark matter experiments using ~50 tons of liquid xenon (LXe). One such technology is silicon photomultipliers (SiPM). SiPM have very low radioactivity, compact geometry, low operation voltages and reasonable photo-detection efficiency for vacuum ultra violet (VUV) light. However, current SiPM still have ~two order of magnitude higher dark count rate compared to PMTs. In order to solve this problem, we are currently developing a new SiPM with the help of Hamamatsu. In this paper, we report the current status of the performance measurements of the new SiPM developed with Hamamatsu to improve the dark count rate (DCR).
Large area photo-detection system using 3” PMTs for the Hyper-Kamiokande Outer-Detector
Authors: Zsoldos Stephane
Published: March 2020

Hyper-Kamiokande, scheduled to begin construction as soon as 2020, is a next generation underground water Cherenkov detector, based on the highly successful Super- Kamiokande experiment. It will serve as a far detector, 295 km away, of a long baseline neutrino experiment for the upgraded J-PARC beam in Japan. It will also be a detector capable of observing — far beyond the sensitivity of the Super-Kamiokande detector — proton decay, atmospheric neutrinos, and neutrinos from astronomical sources.

An Outer Detector (OD) consisting of PMTs mounted behind the inner detector PMTs and facing outwards to view the outer shell of the cylindrical tank, would provide topological information to identify interactions originating from particles outside the inner detector. Any optimization would lead to a significant improvement for the physics goals of the experiment, which are the measurement of the CP leptonic phase and the determination of the neutrino mass hierarchy.

An original setup using small 3” PMTs is being designed for the Hyper-Kamiokande OD. They would give better redundancy, spatial, and angular resolution, as they would be twice or three times more photosensors that the original 8” design proposal of the experiment, and for a reduce cost. Several 3” PMTs candidates considered for the Hyper-Kamiokande OD have been characterized at Queen Mary University London. They all show a very low dark counts and good collection efficiency, which makes them excellent choice to be used in the experiment.
Characterization of the Sos Enattos site for the Einstein Telescope
Authors: Naticchioni L , Boschi V , Calloni E , Capello M , Cardini A , Carpinelli M , Cuccuru S , D’Ambrosio M , de Rosa R , Di Giovanni M , d’Urso D , Fiori I , Gaviano S , Giunchi C , Majorana E , Migoni C , Oggiano G , Olivieri M , Paoletti F , Paratore M , Perciballi M , Piccinini D , Punturo M , Puppo P , Rapagnani P , Ricci F , Saccorotti G , Sipala V , Tringali M C
Published: March 2020

In this work we report the ongoing characterization of the Sos Enattos former mine (Sardinia, Italy), one of the two candidate sites for the Einstein Telescope (ET), the European third-generation underground interferometric detector of Gravitational Waves. The Sos Enattos site lies on a crystalline basement, made of rocks with good geomechanical properties, characterized by negligible groundwater. In addition, the site has a very low seismic background noise due to the absence of active tectonics involving Sardinia. Finally, the area has a low population density, resulting in a reduced anthropic noise even at the ground level. This location was already studied in 2012-2014 as a promising site for an underground detector. More recently, in March 2019, we deployed a new network of surface and underground seismometers at the site, that is currently monitoring the local seismic noise. Most of the energy carried by the seismic waves is due to the microseisms below 1 Hz, showing a significant correlation with the waves of the west Mediterranean sea. Above 1 Hz the seismic noise in the underground levels of the mine approaches the Peterson’s low noise model. Exploiting mine blasting works into the former mine, we were also able to perform active seismic measurements to evaluate the seismic waves propagation across the area. In conclusion we also give a first assessment about the acoustic and magnetic noise in this underground site.
Sagnac gyroscopes, GINGERINO, and GINGER
Authors: Bosi Filippo , Di Virgilio Angela D. V. , Giacomelli Umberto , Simonelli Andrea , Terreni Giuseppe , Basti Andrea , Beverini Nicolò , Carelli Giorgio , Ciampini Donatella , Fuso Francesco , Maccioni Enrico , Marsili Paolo , Stefani Fabio , Ortolan Antonello , Porzio Alberto , Altucci Carlo , Bajardi Francesco , Capozziello Salvatore , Velotta Raffele
Published: March 2020

GINGER (Gyroscopes IN GEneral Relativity), based on an array of large dimension ring laser gyroscopes, is aiming at testing on Earth General Relativity effects, like the gravito-electric and gravito-magnetic effects (also known as De Sitter and Lense-Thirring effects) and the Lorentz violation. The sensitivity is a function of the size and of the losses of the ring laser optical cavity. In this kind of measurement long term stability is matter of concern, and underground location is desirable for its natural thermal stability and for being isolated from atmospheric disturbances. Considering the present sensitivity of the RLG prototype GINGERINO, and assuming total losses of 6 ppm, a 40 m perimeter and 1 day of integration time, a sensitivity of the order of frad/s could be achieved. The construction of GINGER is at present under discussion.