Fri·Apr 26, 2019Friday·April 26, 2019

1. 01*

   Frequency variation for in vacuo photon propagation in the Standard-Model Extension

   José A. Helayël-Neto🇧🇷 · Alessandro D.A.M. Spallicci🇫🇷

   In the presence of Lorentz Symmetry Violation (LSV) associated with the Standard-Model Extension (SME), we have recently shown the non-conservation of the energy-momentum tensor of a light-wave crossing an Electro-Magnetic (EM) background field even when the latter and the LSV are constant. Incidentally, for a space-time dependent LSV, the presence of an EM field is not necessary. Herein, we infer that in a particle description, the energy non-conservation for a photon implies violation of frequency invariance in vacuo giving rise to a red or blue shift. We discuss the potential consequences on cosmology.

   hep-phastro-ph.COgr-qcEPJC(2019)·16 citations
2. 02*

   Flavor from the double tetrahedral group without supersymmetry: flavorful axions and neutrinos

   Christopher D. Carone🇺🇸 · Marco Merchand🇺🇸

   We extend the work of Carone, Chaurasia and Vasquez on non-supersymmetric models of flavor based on the double tetrahedral group. Three issues are addressed: (1) the sector of flavor-symmetry-breaking fields is simplified and their potential studied explicitly, (2) a flavorful axion is introduced to solve the strong CP problem and (3) the model is extended to include the neutrino sector. We show how the model can accommodate the strong hierarchies manifest in the charged fermion Yukawa matrices, while predicting a qualitatively different form for the light neutrino mass matrix that is consistent with observed neutrino mass squared differences and mixing angles.

   hep-phPRD(2019)·16 citations
3. 03*

   Comparison of QCD Curves with Elastic pp Scattering Data

   H.M. Fried🇺🇸 · P.H. Tsang🇺🇸 · Y. Gabellini🇫🇷 · T. Grandou🇫🇷 · Y.M. Sheu🇺🇸

   Using previously described functional techniques for some non--perturbative, gauge invariant, renormalized QCD processes, a simplified version of the amplitudes --- in which forms akin to Pomerons naturally appear --- provides fits to ISR and LHC--TOTEM $pp$ elastic scattering data. Those amplitudes rely on a specific function $\phi (\vec{b})$ which describes the fluctuations of the transverse position of quarks inside hadrons.

   hep-phhep-thInt.J.Mod.Phys.A(2020)·5 citations
4. 04*

   Indirect Studies of Electroweakly Interacting Particles at 100 TeV Hadron Colliders

   Tomohiro Abe🇯🇵 · So Chigusa🇯🇵 · Yohei Ema🇩🇪 · Takeo Moroi🇯🇵

   There are many extensions of the standard model that predict the existence of electroweakly interacting massive particles (EWIMPs), in particular in the context of the dark matter. In this paper, we provide a way for indirectly studying EWIMPs through the precise study of the pair production processes of charged leptons or that of a charged lepton and a neutrino at future 100 TeV collider experiments. It is revealed that this search method is suitable in particular for Higgsino, providing us the $5\sigma$ discovery reach of Higgsino in supersymmetric model with mass up to 850 GeV. We also discuss how accurately one can extract the mass, gauge charge, and spin of EWIMPs in our method.

   hep-phPRD(2019)·9 citations
5. 05*

   Direct Detections of Dark Matter in the Presence of Non-standard Neutrino Interactions

   Wei Chao🇨🇳 · Jian-guo Jiang🇨🇳 · Xuan Wang🇨🇳 · Xing-yu Zhang🇨🇳

   In this paper we investigate impacts of non-standard neutrino interactions (NSIs) to the limitations on the discovery potential of dark matter in direct detection experiments. New neutrino floors are derived taking into account current upper bounds on the effective couplings of various NSIs. Our study shows that the neutrino floors of the standard model neutral current interactions can be significantly changed in the presence of vector-current NSI and scalar-current NSI, and the neutrino floors can be raised up to about $\mathcal{O}(20\%)$ in the presence of pseudo-scalar-current NSI, and there are almost no impacts to the neutrino floors from the axial-vector NSI and the tensor NSI. We suggest combining the dark matter direct detection experiments with the coherent elastic neutrino nucleus scattering experiments to hunt for new physics behind the signal of nuclear recoil in the future.

   hep-phJCAP(2019)·18 citations
6. 06*

   Small t elastic scattering and the rho parameter

   A Donnachie🇬🇧 · P V Landshoff🇬🇧

   A simple application of Regge theory, with 9 free parameters, provides a good fit to elastic scattering data at small t from 13.76 GeV to 13 TeV. It yields a value for rho, the ratio of the real part of the forward amplitude to its imaginary part, close to 0.14 at 13 TeV. Although the exact value obtained for rho is sensitive to what functional form is chosen for the fit, there is no strong case for the presence of an odderon contribution to forward scattering.

   hep-phhep-exPLB(2019)·34 citations
7. 07*

   Quantum field theory of axion-photon mixing and vacuum polarization

   Antonio Capolupo🇮🇹

   We report on recent results obtained by analyzing axion--photon mixing in the framework of quantum field theory. We obtain corrections to the oscillation formulae and we reveal a new effect of the vacuum polarization due to the non-zero value of the vacuum energy for the component of the photon polarization mixed with the axion. The study of axion--photon mixing in curved space is also presented. Numerical analysis show that some quantum field theory effect of axion--photon mixing, in principle, could be detected experimentally.

   hep-phhep-thJ.Phys.Conf.Ser.(2019)·1 citation
8. 08*

   Neutrino nature, total and geometric phase

   A. Capolupo🇮🇹 · S.M. Giampaolo🇭🇷

   We study the total and the geometric phase associated with neutrino mixing and we show that the phases produced by the neutrino oscillations have different values depending on the representation of the mixing matrix and on the neutrino nature. Therefore the phases represent a possible probe to distinguish between Dirac and Majorana neutrinos.

   hep-phJ.Phys.Conf.Ser.(2019)·1 citation
9. 09*

   Real time warm pions from the lattice using an effective theory

   Sourendu Gupta🇮🇳 · Rishi Sharma🇮🇳

   Lattice measurements provide adequate information to fix the parameters of long distance effective field theories in Euclidean time. Using such a theory, we examine the analytic continuation of long distance correlation functions of composite operators at finite temperature from Euclidean to Minkowski space time. There are two definitions of mass in each regime; in Euclidean these are the screening and pole masses. The analytic continuation of these mass parameters to real time is non-trivial. This is in contrast to the situation at zero temperature.

   hep-phhep-lathep-th1 citation
10. 10*

    Charmed Baryon Weak Decays with Decuplet Baryon and SU(3) Flavor Symmetry

    Chao-Qiang Geng🇨🇳 · Chia-Wei Liu🇹🇼 · Tien-Hsueh Tsai🇹🇼 · Yao Yu🇨🇳

    We study the branching ratios and up-down asymmetries in the charmed baryon weak decays of ${\mathbf{B}}_c\to {\mathbf{B}}_{D}M$ with ${\mathbf{B}}_{c(D)}$ anti-triplet charmed (decuplet) baryon and $M$ pseudo-scalar meson states based on the flavor symmetry of $SU(3{)}_F$. We propose equal and physical-mass schemes for the hadronic states to deal with the large variations of the decuplet baryon momenta in the decays in order to fit with the current experimental data. We find that our fitting results of $\mathcal{B}({\mathbf{B}}_c\to {\mathbf{B}}_{D}M)$ are consistent with the current experimental data in both schemes, while the up-down asymmetries in all decays are found to be sizable, consistent with the current experimental data, but different from zero predicted in the literature. We also examine the processes of ${\Xi }_c^0\to {\Sigma }^{\prime 0}{K}_S/K_L$ and derive the asymmetry between the $K_L/K_S$ modes being a constant.

    hep-phhep-exPRD(2019)·32 citations
11. 11*

    The mass and residues of radially and orbitally excited doubly heavy baryons in QCD

    T.M.Aliev🇹🇷 · S.Bilmis🇹🇷

    The mass and residues of the first radial and orbital excitations of $J=\frac{1}{2}$ baryons containing two heavy quarks (b or c) are calculated within the QCD sum rules method. In calculations, the general forms of the interpolating currents with symmetric and anti-symmetric forms with respect to the exchange of heavy quarks have been used. Our results on the spectroscopic parameters of doubly heavy baryons are compared with the predictions of other theoretical approaches.

    hep-phNPA(2019)·17 citations
12. 12*

    Radiative decays of the p-wave charmed heavy baryons

    T.M.Aliev · T. Barakat🇸🇦 · M.Savci

    The radiative decays of the p-wave charmed heavy baryons to the ground state baryon states are studied in the framework of the light cone QCD sum rules method. Firstly, the transition form factors that describe these transitions are estimated, and then using these form factors the corresponding decay widths are calculated. A comparison of our results on the decay widths with those predicted by the other approaches existing in literature is performed.

    hep-phEPJC(2019)·7 citations
13. 13*

    Timing the Neutrino Signal of a Galactic Supernova

    Rasmus S. L. Hansen🇩🇪 · Manfred Lindner🇩🇪 · Oliver Scholer🇩🇪

    We study several methods for timing the neutrino signal of a Galactic supernova (SN) for different detectors via Monte Carlo simulations. We find that, for the methods we studied, at a distance of $10$kpc both Hyper-Kamiokande and IceCube can reach precisions of $\sim 1$ms for the neutrino burst, while a potential IceCube Gen2 upgrade will reach submillisecond precision. In the case of a failed SN, we find that detectors such as SK and JUNO can reach precisions of $\sim 0.1$ms while HK could potentially reach a resolution of $\sim 0.01$ms so that the impact of the black hole formation process itself becomes relevant. Two possible applications for this are the triangulation of a (failed) SN as well as the possibility to constrain neutrino masses via a time-of-flight measurement using a potential gravitational wave signal as reference.

    hep-phastro-ph.HEastro-ph.SRhep-exPRD(2020)·38 citations
14. 14*

    TeV-Scale Thermal WIMPs: Unitarity and its Consequences

    Juri Smirnov (Southern Denmark U., CP3-Origins)🇩🇰 · John F. Beacom (Ohio State U.)🇺🇸

    We re-examine unitarity bounds on the annihilation cross section of thermal-WIMP dark matter. For high-mass pointlike dark matter, it is generic to form WIMP bound states, which, together with Sommerfeld enhancement, affects the relic abundance. We show that these effects lower the unitarity bound from 139 TeV to below 100 TeV for non-self-conjugate dark matter and from 195 TeV (the oft-quoted value of 340 TeV assumes ${\Omega }_{DM}{h}^2=1$) to 140 TeV for the self-conjugate case. For composite dark matter, for which the unitarity limit on the radius was thought to be mass-independent, we show that the largest allowed mass is 1 PeV. In addition, we find important new effects for annihilation in the late universe. For example, while the production of high-energy light fermions in WIMP annihilation is suppressed by helicity, we show that bound-state formation changes this. Coupled with rapidly improving experimental sensitivity to TeV-range gamma rays, cosmic rays, and neutrinos, our results give new hope to attack the thermal-WIMP mass range from the high-mass end.

    hep-phastro-ph.HEPRD(2019)·138 citations
15. 15*

    Neutrino Emission as Diagnostics of Core-Collapse Supernovae

    B. Müller (Monash University)🇦🇺

    With myriads of detection events from a prospective Galactic core-collapse supernova, current and future neutrino detectors will be able to sample detailed, time-dependent neutrino fluxes and spectra. This offers enormous possibilities for inferring supernova physics from the various phases of the neutrino signal from the neutronization burst through the accretion and early explosion phase to the cooling phase. The signal will constrain the time evolution of bulk parameters of the young proto-neutron star like its mass and radius as well as the structure of the progenitor, probe multi-dimensional phenomena in the supernova core, and constrain thedynamics of the early explosion phase. Aside from further astrophysical implications, supernova neutrinos may also shed further light on the properties of matter at supranuclear densities and on open problems in particle physics.

    ↳ astro-ph.HEastro-ph.SRhep-exhep-phAnn.Rev.Nucl.Part.Sci.(2019)·93 citations
16. 16*

    Leaving the Swampland: Non-geometric fluxes and the Distance Conjecture

    Nana Cabo Bizet🇲🇽 · Cesar Damian🇲🇽 · Oscar Loaiza-Brito🇲🇽 · Damian Mayorga Peña🇲🇽

    We study a Type IIB isotropic toroidal compactification with non-geometric fluxes. Under the assumption of a hierarchy on the moduli, an effective scalar potential is constructed showing a runaway direction on the real part of the Kähler modulus while the rest of the moduli are stabilized. For the effective model to be consistent it is required that displacements in the field space are finite. Infinite distances in field space would imply a breakdown in the hierarchy assumption on the moduli. In this context, the Swampland Distance Conjecture is satisfied suggesting the possibility of leaving or entering the Swampland by a parametric control of the fluxes. This is achieved upon allowing the non-geometric fluxes to take fractional values. In the process we are able to compute the cut-off scale below which the theory is valid, completely depending on the flux configuration. We also report on the appearance of a discrete spectrum of values for the string coupling at the level of the effective theory.

    ↳ hep-thhep-phJHEP(2019)·18 citations
17. 17*

    Diagnosing the remnants of binary neutron star merger from GW170817/GRB170817A event

    Hou-Jun Lü🇨🇳 · Jun Shen🇨🇳 · Lin Lan🇨🇳 · Jared Rice🇺🇸 · Wei-Hua Lei🇨🇳 · En-Wei Liang🇨🇳

    The event GW170817/GRB 170817A, discovered via the successful joint observation of its gravitational wave radiation and its multi-wavelength electromagnetic counterparts, was the first definite "smoking-gun" from the merger of two neutron stars (NSs). However, the remnant of the merger remains unknown. Piro et al. recently claimed that a low-significance X-ray variability in GRB 170817A. By systematically comparing the properties of variability in the afterglow of GRB 170817A and X-ray flares in GRB afterglows, we find that this X-ray variability seems to share similar statistical correlations with X-ray flares in GRB afterglows. We further investigate several possible merger product scenarios to see whether they can produce the observed X-ray variability in GRB 170817A. The first scenario invokes a stable magnetar as the central engine producing the later X-ray variability via differential rotation or fall-back accretion onto the NS. The second scenario invokes a black hole as the central engine with a fall-back accretion process. The final scenario is a central engine with a long-lived supra-massive NS. We find that the first two scenarios have difficulty producing the later X-ray variability, which requires either an impractical NS magnetic field or an extraordinarily large stellar envelope and an extremely long accretion timescale. However, the third scenario seems to be consistent with observations, and the later X-ray variability can be produced by the magnetosphere which is expelled following the collapse of the NS with a $B_p\in (3.6,13.5)\times 10^{13}$ G.

    ↳ astro-ph.HEhep-phMNRAS(2019)·15 citations
18. 18*

    Causal hydrodynamic fluctuations in non-static and inhomogeneous backgrounds

    Koichi Murase🇯🇵

    To integrate hydrodynamic fluctuations, namely thermal fluctuations of hydrodynamics, into dynamical models of high-energy nuclear collisions based on relativistic hydrodynamics, the property of the hydrodynamic fluctuations given by the fluctuation-dissipation relation should be carefully investigated. The fluctuation-dissipation relation for causal dissipative hydrodynamics with the finite relaxation time is naturally given in the integral form of the constitutive equation by the linear-response theory. While, the differential form of the constitutive equation is commonly used in analytic investigations and dynamical calculations for practical reasons. We give the fluctuation-dissipation relation for the general linear-response differential form and discuss the restrictions to the structure of the differential form, which comes from the causality and the positive semi-definiteness of the noise autocorrelation, and also the relation of those restrictions to the cutoff scale of the hydrodynamic fluctuations. We also give the fluctuation-dissipation relation for the integral form in non-static and inhomogeneous background by introducing new tensors, the pathline projectors. We find new modification terms to the fluctuation-dissipation relation for the differential form in non-static and inhomogeneous background which are particularly important in dynamical models to describe rapidly expanding systems.

    ↳ nucl-thhep-phnucl-exAnnals Phys.(2019)·19 citations
19. 19*

    Reexamining Ginzburg-Landau theory for neutron ${}^3{P}_2$ superfluidity in neutron stars

    Shigehiro Yasui🇯🇵 · Chandrasekhar Chatterjee🇯🇵 · Michikazu Kobayashi🇯🇵 · Muneto Nitta🇯🇵

    The Ginzburg-Landau (GL) effective theory is a useful tool to study a superconductivity or superfluidity near the critical temperature, and usually the expansion up to the 4th order in terms of order parameters is sufficient for the description of the second-order phase transition. In this paper, we discuss the GL equation for the neutron ${}^3{P}_2$ superfluidity relevant for interior of neutron stars. We derive the GL expansion up to the 8th order in the condensates and find that this order is necessary for the system to have the unique ground state, unlike the ordinary cases. Starting from the $LS$ potential, which provides the dominant attraction between two neutrons at the high density, we derive the GL equation in the path-integral formalism, where the auxiliary field method and the Nambu-Gor'kov representation are used. We present the detailed description for the trace calculation necessary in the derivation of the GL equation. As numerical results, we show the phase diagram of the neutron ${}^3{P}_2$ superfluidity on the plane spanned by the temperature and magnetic field, and find that the 8th order terms lead to a first-order phase transition, whose existence was predicted in the Bogoliubov-de Gennes equation but has not been found thus far within the framework of the GL expansion up to the 6th order.The first-order phase transition will affect the interior structures inside the neutron stars.

    ↳ nucl-thastro-ph.HEcond-mat.supr-conhep-phPRC(2019)·23 citations
20. 20*

    Scale-invariant Helical Magnetic Fields from Inflation

    Tomohiro Fujita🇯🇵 · Ruth Durrer🇨🇭

    We discuss a model which can generate scale-invariant helical magnetic fields on large scales ($\lesssim 1$Mpc) in the primordial universe. It is also shown that the electric conductivity becomes significant and terminates magnetogenesis even before reheating is completed. By solving the electromagnetic dynamics taking conductivity into account, we find that magnetic fields with amplitude $B\simeq 10^{-15}\mathrm{G}$ at present can be generated without encountering a backreaction or strong coupling problem.

    ↳ astro-ph.COgr-qchep-phJCAP(2019)·47 citations
21. 21*

    Signs of Interacting Vacuum and Dark Matter in the Universe

    Joan Sola🇪🇸 · A. Gomez-Valent🇪🇸 · J. de Cruz Perez🇪🇸

    We consider the impact of dynamical dark energy (DDE) in the possible solution of the existing tensions in the $\Lambda$CDM. We test both interacting and non-interacting DE models with dark matter (DM). Among the former, the running vacuum model (RVM) interacting with DM appears as a favored option. The non-interacting scalar field model based on the potential $V\sim {\varphi }^{-\alpha }$, and the generic XCDM parametrization, also provide consistent signs of DDE. The important novelty of our analysis with respect to the existing ones in the literature is that we use the matter bispectrum, together with the power spectrum. Using a complete and updated set of cosmological observations on $SNIa+BAO+H(z)+LSS+CMB$, we find that the crucial triad $BAO+LSS+CMB$ (i.e. baryonic acoustic oscillations, large scale structure formation data and the cosmic microwave background) provide the bulk of the signal. The bispectrum data is instrumental to get hold of the DDE signal, as our analysis shows. If the bispectrum is not included, the DDE signal could not be currently perceived at a significant confidence level.

    ↳ astro-ph.COgr-qchep-ph4 citations
22. 22*

    Bulk quantities in nuclear collisions from running coupling $k_T$-factorization and hybrid simulations

    Andre V. Giannini🇧🇷 · Frédérique Grassi🇧🇷 · Matthew Luzum🇧🇷

    Starting from a Color Glass Condensate (CGC) framework, based on a running-coupling improved $k_T$-factorized formula, we calculate bulk observables in several heavy-ion collision systems. This is done in two ways: first we calculate the particle distribution directly implied from the CGC model, and we compare this to the case where it is instead used as initial conditions for a hybrid hydrodynamic simulation. In this way, we can assess the effects of hydrodynamic and hadronic evolution by quantifying how much they change the results from a pure initial state approach and, therefore, to what extent initial condition models can be directly compared to experimental data. We find that entropy production in subsequent hydrodynamic evolution can increase multiplicity by as much as 50\%. However, disregarding a single overall normalization factor, the centrality, energy, and system size dependence of charged hadron multiplicity is only affected at the $\sim$5\% level. Because of this, the parameter-free prediction for these dependencies gives reasonable agreement with experimental data whether or not hydrodynamic evolution is included. On the other hand, our model results are not compatible with the hypothesis that hydrodynamic evolution is present in large systems, but not small systems like p-Pb, in which case the dependence of multiplicity on system size would be stronger than seen experimentally. Moreover, we find that hydrodynamic evolution significantly changes the distribution of momentum, so that observables such as mean transverse momentum are very different from the initial particle production, and much closer to measured data. Finally, we find that a good agreement to anisotropic flow data cannot be achieved due to the large eccentricity generated by this model.

    ↳ nucl-thhep-phPRC(2019)·2 citations
23. 23*

    Neutrino event generators: foundation, status and future

    Ulrich Mosel🇩🇪

    Neutrino event generators are an essential tool needed for the extraction of neutrino mixing parameters, the mass hierarchy and a CP violating phase from long-baseline experiments. In this article I first describe the theoretical basis and the approximations needed to get to present-days generators. I also discuss the strengths and limitations of theoretical models used to describe semi-inclusive neutrino-nucleus reactions. I then confront present day's generators with this theoretical basis by detailed discussions of the various reaction processes. Finally, as examples I then show for various experiments results of the generator GiBUU for lepton semi-inclusive cross sections as well as particle spectra. I also discuss features of these cross sections in terms of the various reaction components, with predictions for DUNE. Finally, I argue for the need for a new neutrino generator that respects our present-day knowledge of both nuclear theory and nuclear reactions and is as much state-of-the-art as the experimental equipment. I outline some necessary requirements for such a new generator.

    ↳ hep-exhep-phnucl-exnucl-thJ.Phys.G(2019)·75 citations
24. 24*

    Correlations far from equilibrium in charged strongly coupled fluids subjected to a strong magnetic field

    Casey Cartwright🇺🇸 · Matthias Kaminski🇺🇸

    Within a holographic model, we calculate the time evolution of 2-point and 1-point correlation functions (of selected operators) within a charged strongly coupled system of many particles. That system is thermalizing from an anisotropic initial charged state far from equilibrium towards equilibrium while subjected to a constant external magnetic field. One main result is that thermalization times for 2-point functions are significantly (approximately three times) larger than those of 1-point functions. Magnetic field and charge amplify this difference, generally increasing thermalization times. However, there is also a competition of scales between charge density, magnetic field, and initial anisotropy, which leads to an array of qualitative changes on the 2- and 1-point functions. There appears to be a strong effect of the medium on 2-point functions at early times, but approximately none at later times. At strong magnetic fields, an apparently universal thermalization time emerges, at which all 2-point functions appear to thermalize regardless of any other scale in the system. Hence, this time scale is referred to as saturation time scale. As extremality is approached in the purely charged case, 2- and 1-point functions appear to equilibrate at infinitely late time. We also compute 2-point functions of charged operators. Our results can be taken to model thermalization in heavy ion collisions, or thermalization in selected condensed matter systems.

    ↳ hep-thcond-mat.str-elhep-phnucl-ex+1JHEP(2019)·23 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.