pinecone/core-2020-05-10-deduplication huggingface dataset:
A First Experimental Limit on In-matter Torsion from Neutron Spin
  Rotation in Liquid He-4

We report the first experimental upper bound to our knowledge on possible
in-matter torsion interactions of the neutron from a recent search for parity
violation in neutron spin rotation in liquid He-4. Our experiment constrains a
coefficient $\zeta$ consisting of a linear combination of parameters involving
the time components of the torsion fields $T^\mu$ and $A^\mu$ from the nucleons
and electrons in helium which violates parity. We report an upper bound of
$|\zeta|<9.1x10^{-23}$ GeV at 68% confidence level and indicate other physical
processes that could be analyzed to constrain in-matter torsion.Comment: 12 pages, typo correcte
Quantum Fisher Information of W States in Decoherence Channels

We study the quantum Fisher information (QFI) of W states analytically with
respect to SU(2) rotations in the basic decoherence channels i.e. depolarizing
(DPC), amplitude damping (ADC) and phase damping (PDC), and present the
interesting behavior of QFI of W states, especially when compared to that of
GHZ states [Ma et al., Phys. Rev. A, 84, 022302 (2011)]. We find that when
initially pure W states are under decoherence, i) DPC: as decoherence starts
and increases, QFI smoothly decays; ii) ADC: just as decoherence starts, QFI
exhibits a sudden drop to the shot noise level and as decoherence increases,
QFI continues to decrease to zero and then increases back to the shot noise
level; iii) PDC: just as decoherence starts, a sudden death of QFI occurs and
QFI remains zero for any rate of decoherence, therefore W states in phase
damping channel do not provide phase sensitivity. We also find that, on the
contrary to GHZ states, pure or decohered W states are not sensitive with
respect to rotations in z direction and the sensitivities with respect to
rotations in x and y directions are equal to each other, implying no sudden
change points of QFI due to competition between directions.Comment: 3 pages, 1 (eps) figure. Comments are welcom
Decay Constants of Pseudoscalar $D$-mesons in Lattice QCD with
  Domain-Wall Fermion

We present the first study of the masses and decay constants of the
pseudoscalar $ D $ mesons in two flavors lattice QCD with domain-wall fermion.
The gauge ensembles are generated on the $24^3 \times 48 $ lattice with the
extent $ N_s = 16 $ in the fifth dimension, and the plaquette gauge action at $
\beta = 6.10 $, for three sea-quark masses with corresponding pion masses in
the range $260-475$ MeV. We compute the point-to-point quark propagators, and
measure the time-correlation functions of the pseudoscalar and vector mesons.
The inverse lattice spacing is determined by the Wilson flow, while the strange
and the charm quark masses by the masses of the vector mesons $ \phi(1020) $
and $ J/\psi(3097) $ respectively. Using heavy meson chiral perturbation theory
(HMChPT) to extrapolate to the physical pion mass, we obtain $ f_D =
202.3(2.2)(2.6) $ MeV and $ f_{D_s} = 258.7(1.1)(2.9) $ MeV.Comment: 15 pages, 3 figures. v2: the statistics of ensemble (A) with m_sea =
  0.005 has been increased, more details on the systematic error, to appear in
  Phys. Lett.
Radiative and Seesaw Threshold Corrections to the $S_3$ Symmetric
  Neutrino Mass Matrix

We systematically analyze the radiative corrections to the $S_3$ symmetric
neutrino mass matrix at high energy scale, say the GUT scale, in the charged
lepton basis. There are significant corrections to the neutrino parameters both
in the Standard Model (SM) and Minimal Supersymmetric Standard Model (MSSM)
with large tan$\beta$, when the renormalization group evolution (RGE) and
seesaw threshold effects are taken into consideration. We find that in the SM
all three mixing angles and atmospheric mass squared difference are
simultaneously obtained in their current 3$\sigma$ ranges at the electroweak
scale. However, the solar mass squared difference is found to be larger than
its allowed 3$\sigma$ range at the low scale in this case. There are
significant contributions to neutrino masses and mixing angles in the MSSM with
large tan$\beta$ from the RGEs even in the absence of seesaw threshold
corrections. However, we find that the mass squared differences and the mixing
angles are obtained in their current 3$\sigma$ ranges at low energy when the
seesaw threshold effects are also taken into account in the MSSM with large
tan$\beta$.Comment: 20 Pages, 2 Figures and 2 Table
The NLO contributions to the scalar pion form factors and the ${\cal
  O}(\alpha_s^2)$ annihilation corrections to the $B\to \pi\pi$ decays

In this paper, by employing the $k_{T}$ factorization theorem, we made the
first calculation for the space-like scalar pion form factor $Q^2 F(Q^2)$ at
the leading order (LO) and the next-to-leading order (NLO) level, and then
found the time-like scalar pion form factor $F'^{(1)}_{\rm a,I}$ by analytic
continuation from the space-like one. From the analytical evaluations and the
numerical results, we found the following points: (a) the NLO correction to the
space-like scalar pion form factor has an opposite sign with the LO one but is
very small in magnitude, can produce at most $10\%$ decrease to LO result in
the considered $Q^2$ region; (b) the NLO time-like scalar pion form factor
$F'^{(1)}_{\rm a,I}$ describes the ${\cal O}(\alpha_s^2)$ contribution to the
factorizable annihilation diagrams of the considered $B \to \pi\pi$ decays,
i.e. the NLO annihilation correction; (c) the NLO part of the form factor
$F'^{(1)}_{\rm a,I}$ is very small in size, and is almost independent with the
variation of cutoff scale $\mu_0$, but this form factor has a large strong
phase around $-55^\circ$ and may play an important role in producing large CP
violation for $B\to \pi\pi$ decays; and (d) for $B^0 \to \pi^+\pi^-$ and $
\pi^0\pi^0$ decays, the newly known NLO annihilation correction can produce
only a very small enhancement to their branching ratios, less than $3\%$ in
magnitude, and therefore we could not interpret the well-known $\pi\pi$-puzzle
by the inclusion of this NLO correction to the factorizable annihilation
diagrams.Comment: 26 pages, 12 figures, 1 Table; Minor correction
A note on the dual of N=1 super Yang-Mills theory

We refine the dictionary of the gauge/gravity correspondence realizing N=1
super Yang-Mills by means of D5-branes wrapped on a resolved Calabi-Yau space.
This is done by fixing an ambiguity on the correct interpretation of the
holographic dual of the running gauge coupling and amounts to identify a
specific 2-cycle in the dual ten-dimensional supergravity background. In doing
so, we also discuss the role played in this context by gauge transformations in
the relevant seven-dimensional gauged supergravity. While all nice properties
of the duality are maintained, this modification of the dictionary has some
interesting physical consequences and solves a puzzle recently raised in the
literature. In this refined framework, it is also straightforward to see how
the correspondence naturally realizes a geometric transition.Comment: 11 pages, latex; minor changes and typos correcte
Casimir energy-momentum tensor for a brane in de Sitter spacetime

Vacuum expectation values of the energy-momentum tensor for a conformally
coupled scalar field is investigated in de Sitter (dS) spacetime in presence of
a curved brane on which the field obeys the Robin boundary condition with
coordinate dependent coefficients. To generate the corresponding vacuum
densities we use the conformal relation between dS and Rindler spacetimes and
the results previously obtained by one of the authors for the Rindler
counterpart. The resulting energy-momentum tensor is non-diagonal and induces
anisotropic vacuum stresses. The asymptotic behaviour of this tensor is
investigated near the dS horizon and the boundary.Comment: 10 pages, no figur
Double beta decay to the first $2^+$ state within a boson expansion
  formalism with a projected spherical single particle basis

The Gamow-Teller transition operator is written as a polynomial in the dipole
proton-neutron and quadrupole charge conserving QRPA boson operators, using the
prescription of the boson expansion technique of Belyaev-Zelevinski type. Then,
the $2\nu\beta\beta$ process ending on the first $2^+$ state in the daughter
nucleus is allowed via one, two and three boson states describing the odd-odd
intermediate nucleus. The approach uses a single particle basis which is
obtained by projecting out the good angular momentum from an orthogonal set of
deformed functions. The basis for mother and daughter nuclei have different
deformations. The GT transition amplitude as well as the half lives were
calculated for ten transitions.
  Results are compared with the available data as well as with some predictions
obtained with other methods.Comment: 12 page
Students’ views of oral performance assessment in mathematics: straddling the ‘assessment of’ and ‘assessment for’ learning divide

This paper explores the views of a group of students who took an oral performance assessment in a first year mathematics module. Such assessments are unusual for most subjects in the UK, but particularly within the generally homogenous assessment diet of undergraduate mathematics. The evidence presented here resonates with some, but not all, of the existing literature on oral assessment and suggests that, despite concerns about anxiety and fairness, students see oral assessments as encouraging a focus on understanding, being relatively authentic and reactive to their needs. We argue that, suitably implemented, oral assessment may be a viable assessment method for straddling the ‘assessment for’ and ‘assessment of’ learning divide in higher education
A coordinated optical and X-ray spectroscopic campaign on HD 179949 : searching for planet-induced chromospheric and coronal activity

Context. HD 179949 is an F8V star, orbited by a close-in giant planet with a period of ~3 days. Previous studies suggested that the planet enhances the magnetic activity of the parent star, producing a chromospheric hot spot which rotates in phase with the planet orbit. However, this phenomenon is intermittent since it was observed in several but not all seasons. Aims. A long-term monitoring of the magnetic activity of HD 179949 is required to study the amplitude and time scales of star-planet interactions. Methods. In 2009 we performed a simultaneous optical and X-ray spectroscopic campaign to monitor the magnetic activity of HD 179949 during ~5 orbital periods and ~2 stellar rotations. We analyzed the Ca II H&K lines as a proxy for chromospheric activity, and we studied the X-ray emission in search of flux modulations and to determine basic properties of the coronal plasma. Results. A detailed analysis of the flux in the cores of the Ca II H&K lines and a similar study of the X-ray photometry shows evidence of source variability, including one flare. The analysis of the time series of chromospheric data indicates a modulation with a ~11 days period, compatible with the stellar rotation period at high latitudes. Instead, the X-ray light curve suggests a signal with a period of ~4 days, consistent with the presence of two active regions on opposite hemispheres. Conclusions. The observed variability can be explained, most likely, as due to rotational modulation and to intrinsic evolution of chromospheric and coronal activity. There is no clear signature related to the orbital motion of the planet, but the possibility that just a fraction of the chromospheric and coronal variability is modulated with the orbital period of the planet, or the stellar-planet beat period, cannot be excluded. We conclude that any effect due to the presence of the planet is difficult to disentangle.Publisher PDFPeer reviewe
Particle energisation in a collapsing magnetic trap model : the relativistic regime

The authors acknowledge financial support by the UK’s Science and Technology Facilities Council through a Doctoral Training Grant (SEO) and Consolidated Grant ST/K000950/1 (SEO and TN).Context. In solar flares, a large number of charged particles is accelerated to high energies. By which physical processes this is achieved is one of the main open problems in solar physics. It has been suggested that during a flare, regions of the rapidly relaxing magnetic field can form a collapsing magnetic trap (CMT) and that this trap may contribute to particle energisation. Aims. In this Research Note we focus on a particular analytical CMT model based on kinematic magnetohydrodynamics. Previous investigations of particle acceleration for this CMT model focused on the non-relativistic energy regime. It is the specific aim of this Research Note to extend the previous work to relativistic particle energies. Methods. Particle orbits were calculated numerically using the relativistic guiding centre equations. We also calculated particle orbits using the non-relativistic guiding centre equations for comparison. Results. For mildly relativistic energies the relativistic and non-relativistic particle orbits mainly agree well, but clear deviations are seen for higher energies. In particular, the final particle energies obtained from the relativistic calculations are systematically lower than the energies reached from the corresponding non-relativistic calculations, and the mirror points of the relativistic orbits are systematically higher than for the corresponding non-relativistic orbits. Conclusions. While the overall behaviour of particle orbits in CMTs does not differ qualitatively when using the relativistic guiding centre equations, there are a few systematic quantitative differences between relativistic and non-relativistic particle dynamics.Publisher PDFPeer reviewe
All-loop anomalous dimensions in integrable λ-deformed σ-models

We calculate the all-loop anomalous dimensions of current operators in λ-deformed σ-models. For the isotropic integrable deformation and for a semi-simple group G we compute the anomalous dimensions using two different methods. In the first we use the all-loop effective action and in the second we employ perturbation theory along with the Callan–Symanzik equation and in conjunction with a duality-type symmetry shared by these models. Furthermore, using CFT techniques we compute the all-loop anomalous dimension of bilinear currents for the isotropic deformation case and a general G  . Finally we work out the anomalous dimension matrix for the cases of anisotropic SU(2) and the two couplings, corresponding to the symmetric coset G/H and a subgroup H, splitting of a group G
The morphologies of massive galaxies from z ~ 3-witnessing the two channels of bulge growth

We quantify the morphological evolution of z ~ 0 massive galaxies (M_*/M_∼ ∼10^11.2 +/- 0.3) from z ~ 3 in the 5 CANDELS fields. The progenitors are selected using abundance matching techniques to account for the mass growth. At z < 1, the population matches the massive end of the Hubble sequence, with 30% of pure spheroids, 50% of galaxies with equally dominant disk and bulge components, and 20% of disks. At z ~ 2-3 however, there is a majority of irregular systems (~ 60%-70%) with still 30% of pure spheroids. We then analyze the stellar populations, star formation rates (SFRs), gas fractions, and structural properties for the different morphologies independently. Our results suggest two distinct channels for the growth of bulges in massive galaxies. Around ~ 30%-40% were already bulges at z ~ 2.5, with low average SFRs and gas fractions (10%-15%), high Sersic indices (n > 3-4), and small effective radii (R_e ∼1 kpc), pointing toward an even earlier formation through gas-rich mergers or violent disk instabilities. Between z ~ 2.5 and z ~ 0, they rapidly increase their size by a factor of ~ 4-5, are quenched, and slightly increase their Sersic indices (n ~ 5) but their global morphology remains unaltered. The structural evolution is independent of the gas fractions, suggesting that it is driven by ex situ events. The remaining 60% experience a gradual morphological transformation, from clumpy disks to more regular bulge +disk systems, essentially happening at z > 1. This results in the growth of a significant bulge component (n ~ 3) for 2/3 of the systems, possibly through the migration of clumps, while the remaining 1/3 retain a rather small bulge (n ~ 1.5-2). The transition phase between disturbed and relaxed systems and the emergence of the bulge is correlated with a decrease in the star formation activity and the gas fractions, suggesting a morphological quenching process as a plausible mechanism for the formation of these bulges
Search for excited quarks in the γ+jet final state in proton–proton collisions at s√=8 TeV

A search for excited quarks decaying into the γ+jet final state is presented. The analysis is based on data corresponding to an integrated luminosity of 19.7 fb−1 collected by the CMS experiment in proton–proton collisions at s√ = 8 TeV at the LHC. Events with photons and jets with high transverse momenta are selected and the γ+jet invariant mass distribution is studied to search for a resonance peak. The 95% confidence level upper limits on the product of cross section and branching fraction are evaluated as a function of the excited quark mass. Limits on excited quarks are presented as a function of their mass and coupling strength; masses below 3.5 TeV are excluded at 95% confidence level for unit couplings to their standard model partners
Evidence for the decay $X(3872)\rightarrow\psi(2S)\gamma$

Evidence for the decay mode $X(3872)\rightarrow\psi(2S)\gamma$ in $B^+\rightarrow X(3872)K^+$ decays is found with a significance of 4.4 standard deviations. The analysis is based on a data sample of proton-proton collisions, corresponding to an integrated luminosity of 3fb$^{-1}$ collected with the LHCb detector, at centre-of-mass energies of 7 and 8TeV. The ratio of the branching fraction of the $X(3872)\to\psi(2S)\gamma$ decay to that of the $X(3872)\rightarrow J/\psi \gamma$ decay is measured to be $$ \frac{Br(X(3872)\rightarrow\psi(2S)\gamma)}{Br(X(3872)\rightarrow J/\psi\gamma)} = 2.46\pm0.64\pm0.29, %\pm0.06,$$ where the first uncertainty is statistical and the second is systematic. The measured value agrees with expectations for a pure charmonium interpretation of the $X(3872)$ state and a mixture of charmonium and molecular interpretations. However, it does not support a pure $D\bar{D}^{*}$ molecular interpretation of the $X(3872)$state
Search for neutral color-octet weak-triplet scalar particles in proton-proton collisions at $\sqrt{s}$ = 8 TeV

A search for pair production of neutral color-octet weak-triplet scalar particles ($\theta^0$) is performed in processes where one $\theta^0$ decays to a pair of b quark jets and the other to a $Z$ boson plus a jet, with the Z boson decaying to a pair of electrons or muons. The search is performed with data collected by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of 19.7 $fb^{−1}$ of proton-proton collisions at $\sqrt{s}=8$. The number of observed events is found to be in agreement with the standard model predictions. The 95% confidence level upper limit on the product of the cross section and branching fraction is obtained as a function of the $\theta^0$ mass. The 95% confidence level lower bounds on the $\theta^0$ mass are found to be 623 and 426 GeV, for two different octo-triplet theoretical scenarios. These are the first direct experimental bounds on particles predicted by the octo-triplet mode
Lepton-flavor violations in high-scale SUSY with right-handed neutrinos

Motivated by the recent discovery of the Higgs boson at <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>m</mi></mrow><mrow><mi>h</mi></mrow></msub><mo>≃</mo><mn>126</mn><mtext> GeV</mtext></math> and also by the non-observation of superparticles at the LHC, high-scale SUSY, where the superparticles are as heavy as <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>O</mi><mo stretchy="false">(</mo><mn>10</mn><mo stretchy="false">)</mo><mtext> TeV</mtext></math> , has been recently proposed. We study lepton-flavor violations (LFVs) in the high-scale SUSY with right-handed neutrinos. Even if the slepton masses are of <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>O</mi><mo stretchy="false">(</mo><mn>10</mn><mo stretchy="false">)</mo><mtext> TeV</mtext></math> , the renormalization group (RG) effects on the slepton mass-squared matrix may induce large enough LFVs which are within the reach of future LFV experiments. We also discuss the implication of the right-handed neutrinos on the electroweak symmetry breaking in such a model, and show that the parameter region with the successful electroweak symmetry breaking is enlarged by the RG effects due to the right-handed neutrinos
Finite BRST–antiBRST transformations in Lagrangian formalism

We continue the study of finite BRST–antiBRST transformations for general gauge theories in Lagrangian formalism initiated in [1] , with a doublet λa , a=1,2 , of anticommuting Grassmann parameters, and find an explicit Jacobian corresponding to this change of variables for constant λa . This makes it possible to derive the Ward identities and their consequences for the generating functional of Green's functions. We announce the form of the Jacobian (proved to be correct in [31] ) for finite field-dependent BRST–antiBRST transformations with functionally-dependent parameters, λa=saΛ , induced by a finite even-valued functional Λ(ϕ,π,λ) and by the generators sa of BRST–antiBRST transformations, acting in the space of fields ϕ , antifields ϕa⁎,ϕ¯ and auxiliary variables πa,λ . On the basis of this Jacobian, we present and solve a compensation equation for Λ , which is used to achieve a precise change of the gauge-fixing functional for an arbitrary gauge theory. We derive a new form of the Ward identities, containing the parameters λa , and study the problem of gauge-dependence. The general approach is exemplified by the Freedman–Townsend model of a non-Abelian antisymmetric tensor field
Time dependence in B → V ℓℓ decays

We discuss the theory and phenomenology of B d,s → V (→ M 1 M 2 )ℓℓ decays in the presence of neutral-meson mixing. We derive expressions for the time-dependent angular distributions for decays into CP eigenstates, and identify the relevant observables that can be extracted from time-integrated and time-dependent analyses with or without tagging, with a focus on the difference between measurements at B -factories and hadronic machines. We construct two observables of interest, which we call Q 8 − and Q 9 , and which are theoretically clean at large recoil. We compute these two observables in the Standard Model, and show that they have good potential for New Physics searches by considering their sensitivity to benchmark New Physics scenarios consistent with current b → s ℓℓ data. These results apply to decays such as B d → K ∗ (→ K S π 0 )ℓℓ, B s → ϕ (→ K S K L )ℓℓ and B s → ϕ (→ K + K − )ℓℓ