Wed·Apr 4, 2018Wednesday·April 4, 2018

1. 01*

   Impact of magnetic field on shear viscosity of quark matter in Nambu-Jona-Lasinio model

   Sabyasachi Ghosh🇮🇳 · Bhaswar Chatterjee🇮🇳 · Payal Mohanty🇮🇳 · Arghya Mukharjee🇮🇳 · Hiranmaya Mishra🇮🇳

   We have investigated shear viscosity of quark matter in presence of a strong uniform magnetic field background where Nambu-Jona-Lasinio model has been considered to describe the magneto-thermodynamical properties of the medium. In presence of magnetic field, shear viscosity coefficient gets split into different components because of anisotropy in tangential stress of the fluid. Four different components can be merged to two components in limit of strong field, where collisional width of quark becomes much lower than its synchrotron frequency. A simplified contact diagram of quark-quark interaction can estimate a small collisional width, where strong field limit expressions are exactly applicable. Although, for RHIC or LHC matter, one can expect a large thermal width, for which generalized four components viscosities are necessary. We have explored these all different possible cases in the thermodynamical framework of Nambu-Jona-Lasinio model.

   hep-phnucl-thPRD(2019)·37 citations
2. 02*

   Texture One Zero Dirac Neutrino Mass Matrix With Vanishing Determinant or Trace Condition

   Madan Singh🇮🇳

   In the light of non-zero and relatively large value of rector mixing angle (${\theta }_{13}$), we have performed a detailed analysis of texture one zero neutrino mass matrix $M_{\nu }$ in the scenario of vanishing determinant/trace conditions , assuming the Dirac nature of neutrinos. In both the scenarios, normal mass ordering is ruled out for all the six possibilities of $M_{\nu }$, however for inverted mass ordering, only two are found to be viable with the current neutrino oscillation data at $3\sigma$ confidence level. Numerical and some approximate analytical results are presented.

   hep-phNPB(2018)·9 citations
3. 03*

   Pseudoscalar or vector meson production in non-leptonic decays of heavy hadrons

   Wei-Hong Liang🇨🇳 · E. Oset🇪🇸

   We have addressed the study of non-leptonic weak decays of heavy hadrons (${\Lambda }_b,{\Lambda }_c,B$ and $D$), with external and internal emission to give two final hadrons, taking into account the spin-angular momentum structure of the mesons and baryons produced. A detailed angular momentum formulation is developed which leads to easy final formulas. By means of them we have made predictions for a large amount of reactions, up to a global factor, common to many of them, that we take from some particular data. Comparing the theoretical predictions with the experimental data, the agreement found is quite good in general and the discrepancies should give valuable information on intrinsic form factors, independent of the spin structure studied here. The formulas obtained are also useful in order to evaluate meson-meson or meson-baryon loops, for instance of $B$ decays, in which one has PP, PV, VP or VV intermediate states, with P for pseudoscalar mesons and V for vector meson and lay the grounds for studies of decays into three final particles.

   hep-phEPJC(2018)·13 citations
4. 04*

   Reconstructing the gluon

   Anton K. Cyrol🇩🇪 · Jan M. Pawlowski🇩🇪 · Alexander Rothkopf🇩🇪 · Nicolas Wink🇩🇪

   We reconstruct the gluon spectral function in Landau gauge QCD from numerical data for the gluon propagator. The reconstruction relies on two novel ingredients: Firstly we derive analytically the low frequency asymptotics of the spectral function. Secondly we construct a functional basis from a careful consideration of the analytic properties of the gluon propagator in Landau gauge. This allows us to reliably capture the non-perturbative regime of the gluon spectrum. We also compare different reconstruction methods and discuss the respective systematic errors.

   hep-phhep-lathep-thSciPost Phys.(2018)·113 citations
5. 05*

   Potential observation of the ${\rm Y}(6S)\to {\rm Y}(1^3{D}_J)\eta$ transitions at Belle II

   Qi Huang🇨🇳 · Hao Xu🇨🇳 · Xiang Liu🇨🇳 · Takayuki Matsuki🇯🇵

   We perform the investigation of two-body hidden-bottom transitions of the ${\rm Y}(6S)$, which include ${\rm Y}(6S)\to {\rm Y}(1^3{D}_J)\eta (J=1,2,3)$ decays. For estimating the branching ratios of these processes, we consider contributions from the triangle hadronic loops composed of S-wave $B_{(s)}$ and $B_{(s)}^{\ast }$ mesons, which are a bridge to connect the ${\rm Y}(6S)$ and final states. Our results show that both of the branching ratios of these decays can reach $10^{-3}$. Due to such considerable potential to observe these two-body hidden-bottom transitions of the ${\rm Y}(6S)$, we suggest the forthcoming Belle II experiment to explore them.

   hep-phhep-exPRD(2018)·13 citations
6. 06*

   Light-cone distribution amplitudes of vector meson in large momentum effective theory

   Ji Xu🇨🇳 · Qi-An Zhang🇨🇳 · Shuai Zhao🇨🇳

   We investigate the leading twist light-cone distribution amplitudes (LCDAs) of vector meson in the framework of large momentum effective theory. We derive the matching equation for the LCDAs and quasi distribution amplitudes. The matching coefficients are determined to one loop accuracy, both in the ultraviolet cut-off and dimensional regularization schemes. This calculation provides the possibility of studying the full $x$ behavior of LCDAs and extracting LCDAs of vector mesons from lattice simulations.

   hep-phhep-latPRD(2018)·51 citations
7. 07*

   A Democratic Resummation Procedure of Soft Gluon Emission for Hadronic Inelastic Cross-sections and Survival Probabilities

   Giulia Pancheri🇮🇹 · Yogendra. N. Srivastava🇮🇹

   We discuss a model for soft gluon re-summation based on a statistical description of independent emissions during inelastic collisions. The model is applied to estimate Survival Probabilities at the LHC. A comparison with other models and experimental data is presented.

   hep-phFrascati Phys.Ser.(2017)·0 citations
8. 08*

   Revisiting regularization with Kaluza-Klein states and Casimir vacuum energy from extra dimensional spaces

   Hiroki Matsui🇯🇵 · Yoshio Matsumoto🇯🇵

   In the present paper, we investigate regularization of the one-loop quantum corrections with infinite Kaluza-Klein (KK) states and evaluate Casimir vacuum energy from extra dimensions. The extra dimensional models always involve the infinite massless or massive Kaluza-Klein states, and therefore, the regularization of the infinite KK corrections is highly problematic. In order to avoid the ambiguity, we adopt the proper time integrals and the Riemann zeta function regularization in evaluating the summations of infinite KK states. In the calculation, we utilize the KK regularization method with exchanging the infinite summations and the infinite loop integrals. At the same time, we also evaluate the correction by the the dimensional regularization method without exchanging the summations and the loop integrals. Then, we clearly show that the regularized Casimir corrections from the KK states have the form of $\propto 1/R^2$ for the Higgs mass and $\propto 1/R^4$ for the cosmological constant, where $R$ is the compactification radius. We also evaluate the Casimir energy in supersymmetric extra-dimensional models. The contributions from bulk fermions and bulk bosons are not offset because we choose SUSY breaking boundary conditions. The non-zero supersymmetric Casimir corrections from extra dimensions undoubtedly contribute to the Higgs mass and the cosmological constant. We conclude the coefficients of such corrections are enhanced compared to the case without bulk supersymmetry.

   hep-phgr-qchep-thPRD(2019)·4 citations
9. 09*

   Variation of $\alpha$ from a Dark Matter Force

   Hooman Davoudiasl🇺🇸 · Pier Paolo Giardino🇺🇸

   We consider a long range scalar force that mainly couples to dark matter and unstable Standard Model states, like the muon, with tiny strength. Probing this type of force would present a challenge to observations. We point out that the dependence of the induced background scalar field on dark matter number density can cause the mass of the unstable particles to have spatial and temporal variations. These variations, in turn, leave an imprint on the value of the fine structure constant $\alpha$, through threshold corrections, that could be detected in astronomical and cosmological measurements. Our mechanism can accommodate the mild preference of the Planck data for such a deviation, $({\alpha }_{{}_{\mathrm{CMB}}}-{\alpha }_{\mathrm{present}})/{\alpha }_{\mathrm{present}}=(-3.6\pm 3.7)\times 10^{-3}$. In this case, the requisite parameters typically imply that violations of Equivalence Principle may be within reach of future experiments.

   hep-phastro-ph.COPLB(2019)·20 citations
10. 10*

    Model independent radiative corrections to elastic deuteron-electron scattering

    G.I. Gakh · M.I. Konchatnij · N.P. Merenkov · E. Tomasi-Gustafsson

    The differential cross section for elastic scattering of deuterons on electrons at rest is calculated taking into account the QED radiative corrections to the leptonic part of interaction. These model-independent radiative corrections arise due to emission of the virtual and real soft and hard photons as well as to vacuum polarization. We consider an experimental setup where both final particles are recorded in coincidence and their energies are determined within some uncertainties. The kinematics, the cross section, and the radiative corrections are calculated and numerical results are presented.

    hep-phnucl-thPRC(2018)·9 citations
11. 11*

    Implication of rephasing invariant parameters on texture specific mass matrices

    Madan Singh🇮🇳

    In the quark sector, Jarlskog rephasing invariant parameter $J_{CP}$ has important implications for the CP violation as well as phase structure of the quark mass matrices. In fact all CP violating effects in this sector are proportional to the magnitude of the imaginary part of $J_{CP}$ . With the observation of non-zero and large "reactor mixing angle", it is widely believed that CP might be violated in the leptonic sector. In this context, we have examined in detail the relationship of CP odd invariants for texture specific mass matrices. In particular, we have calculated the predicted ranges of Jarlskog rephasing invariant parameter and other weak basis invariants for all the seven viable cases for texture two zero mass matrices.

    hep-ph0 citations
12. 12*

    Should China build the Great Collider?

    Stephen Hawking🇬🇧 · Gordon Kane🇺🇸

    We address the question of the title from the scientific, economic, and cultural points of view, and argue strongly for a positive answer. We respond to various issues that have been raised.

    ↳ physics.soc-phhep-exhep-phhep-thICCM Not.(2018)·0 citations
13. 13*

    Gravity-mediated Dark Matter models in the de Sitter space

    Ion V. Vancea🇧🇷

    In this paper, we generalize the simplified Dark Matter models with graviton mediator to the curved space-time, in particular to the de Sitter space. We obtain the generating functional of the Green's functions in the Euclidean de Sitter space for the covariant free gravitons. We determine the generating functional of the interacting theory between Dark Matter particles and the covariant gravitons. Also, we calculate explicitly the 2-point and 3-point interacting Green's functions for the symmetric traceless divergence-less covariant graviton. The results derived here are general in the sense that they do not depend on a particular model for the Dark Matter component and they show that the quantum effects of the interaction between the Dark Matter and the gravitons in the de Sitter space are computable by the methods of the standard Quantum Field Theory techniques.

    ↳ hep-thastro-ph.HEgr-qchep-phPhys.Dark Univ.(2018)·3 citations
14. 14*

    Elastic Compton Scattering from 3He and the Role of the Delta

    Arman Margaryan (Duke U.) · Bruno Strandberg (U. of Glasgow and Nikhef) Harald W. Griesshammer (George Washington U.) · Judith A. McGovern (U. of Manchester) · Daniel R. Phillips (Ohio U.) · Deepshikha Shukla (Rockford U.)

    We report observables for elastic Compton scattering from ${}^3$He in Chiral Effective Field Theory with an explicit $\Delta (1232)$ degree of freedom ($\chi$EFT) for energies between 50 and 120 MeV. The $\gamma {}^3$He amplitude is complete at N3LO, $\mathcal{O}(e^2{\delta }^3)$, and in general converges well order by order. It includes the dominant pion-loop and two-body currents, as well as the Delta excitation in the single-nucleon amplitude. Since the cross section is two to three times that for deuterium and the spin of polarised ${}^3$He is predominantly carried by its constituent neutron, elastic Compton scattering promises information on both the scalar and spin polarisabilities of the neutron. We study in detail the sensitivities of 4 observables to the neutron polarisabilities: the cross section, the beam asymmetry and two double asymmetries resulting from circularly polarised photons and a longitudinally or transversely polarised target. Including the Delta enhances those asymmetries from which neutron spin polarisabilities could be extracted. We also correct previous, erroneous results at N2LO, i.e.~without an explicit Delta, and compare to the same observables on proton, neutron and deuterium targets. An interactive Mathematica notebook of our results is available from hgrie@gwu.edu.

    ↳ nucl-thhep-phEPJA(2018)·18 citations
15. 15*

    Combination and QCD analysis of charm and beauty production cross-section measurements in deep inelastic $ep$ scattering at HERA

    H1 · ZEUS collaborations

    Measurements of open charm and beauty production cross sections in deep inelastic $ep$ scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections are obtained in the kinematic range of negative four-momentum transfer squared of the photon $2.5$ GeV${}^2<Q^2<2000$ GeV${}^2$ and Bjorken scaling variable $3\cdot 10^{-5}<x_{\text{Bj}}<5\cdot 10^{-2}$. The combination method accounts for the correlations of the statistical and systematic uncertainties among the different datasets. Perturbative QCD calculations are compared to the combined data. A next-to-leading order QCD analysis is performed using these data together with the combined inclusive deep inelastic scattering cross sections from HERA. The running charm- and beauty-quark masses are determined as $m_c(m_c)=1.290_{-0.041}^{+0.046}{\text{(exp/fit)}}_{-0.014}^{+0.062}{\text{(model)}}_{-0.031}^{+0.003}\text{(parameterisation)}$ GeV and $m_b(m_b)=4.049_{-0.109}^{+0.104}{\text{(exp/fit)}}_{-0.032}^{+0.090}{\text{(model)}}_{-0.031}^{+0.001}\text{(parameterisation)}$~GeV.

    ↳ hep-exhep-phEPJC(2018)·168 citations
16. 16*

    Aspects of Dark Matter Annihilation in Cosmology

    Daniel Green🇺🇸 · P. Daniel Meerburg🇬🇧 · Joel Meyers🇨🇦

    Cosmic microwave background (CMB) constraints on dark matter annihilation are a uniquely powerful tool in the quest to understand the nature of dark matter. Annihilation of dark matter to Standard Model particles between recombination and reionization heats baryons, ionizes neutral hydrogen, and alters the CMB visibility function. Surprisingly, CMB bounds on dark matter annihilation are not expected to improve significantly with the dramatic improvements in sensitivity expected in future cosmological surveys. In this paper, we will present a simple physical description of the origin of the CMB constraints and explain why they are nearly saturated by current observations. The essential feature is that dark matter annihilation primarily affects the ionization fraction which can only increase substantially at times when the universe was neutral. The resulting change to the CMB occurs on large angular scales and leads to a phenomenology similar to that of the optical depth to reionization. We will demonstrate this impact on the CMB both analytically and numerically. Finally, we will discuss the additional impact that changing the ionization fraction has on large scale structure.

    ↳ astro-ph.COhep-phJCAP(2019)·26 citations
17. 17*

    21-cm Fluctuations from Charged Dark Matter

    Julian B. Muñoz🇺🇸 · Cora Dvorkin🇺🇸 · Abraham Loeb🇺🇸

    The epoch of the formation of the first stars, known as the cosmic dawn, has emerged as a new arena in the search for dark matter. In particular, the first claimed 21-cm detection exhibits a deeper global absorption feature than expected, which could be caused by a low baryonic temperature, and has been interpreted as a sign for electromagnetic interactions between baryons and dark matter. This hypothesis has a striking prediction: large temperature anisotropies sourced by the velocity-dependent cooling of the baryons. However, in order to remain consistent with the rest of cosmological observations, only part of the dark matter is allowed to be charged, and thus interactive. Here we compute, for the first time, the 21-cm fluctuations caused by a charged subcomponent of the dark matter, including both the pre- and post-recombination evolution of all fluids. We find that, for the same parameters that can explain the anomalous 21-cm absorption signal, any percent-level fraction of charged dark matter would source novel 21-cm fluctuations with a unique acoustic spectrum, and with an amplitude above any other known effects. These fluctuations are uncorrelated with the usual adiabatic anisotropies, and would be observable at high significance with interferometers such as LOFAR and HERA, thus providing a novel probe of dark matter at cosmic dawn.

    ↳ astro-ph.COastro-ph.IMhep-phPRL(2018)·118 citations
18. 18*

    Momentum distribution and correlation for a free scalar field in the Tsallis nonextensive statistics based on density operator

    Masamichi Ishihara🇯🇵

    We derived the expression of the normalized $q$-expectation value based on the density operator to the order $1-q$ with the physical temperature in the Tsallis nonextensive statistics of entropic parameter $q$. With the derived expression of the normalized $q$-expectation value, we calculated the momentum distribution and the correlation to the order $1-q$ as functions of the inverse physical temperature for a free scalar field. To the order $1-q$, the momentum distribution derived by using the density operator coincides with the momentum distribution derived from the entropic measure described with the distribution, when the physical temperature equals the temperature in the distribution derived from the entropic measure. The correlation depends on the momentums for $q\ne 1$. The factor two appears in the correlation for the same momentums, and indicates that the effects of boson at $q\ne 1$ and those at $q=1$ are similar for the correlation.

    ↳ cond-mat.stat-mechhep-phEPJA(2018)·10 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.