PaperPanorama

HEP Phenomenology·hep-ph

Tue·Feb 18, 2020

36 papers23 primary·13 cross-listed·reconstructed*

  1. 01*

    Uncertainties associated with GAN-generated datasets in high energy physics

    Konstantin T. Matchev🇺🇸 · Alexander Roman🇺🇸 · Prasanth Shyamsundar🇺🇸

    Recently, Generative Adversarial Networks (GANs) trained on samples of traditionally simulated collider events have been proposed as a way of generating larger simulated datasets at a reduced computational cost. In this paper we point out that data generated by a GAN cannot statistically be better than the data it was trained on, and critically examine the applicability of GANs in various situations, including a) for replacing the entire Monte Carlo pipeline or parts of it, and b) to produce datasets for usage in highly sensitive analyses or sub-optimal ones. We present our arguments using information theoretic demonstrations, a toy example, as well as in the form of a formal statement, and identify some potential valid uses of GANs in collider simulations.

    hep-phhep-exphysics.comp-phphysics.data-anSciPost Phys.(2022)·40 citations
  2. 02*

    Masses of tetraquark states in the hidden charm sector above threshold

    Tanvi Bhavsar🇮🇳 · Manan Shah🇮🇳 · Smruti Patel🇮🇳 · P. C. Vinodkumar🇮🇳

    In the diquark-diantiquark composition, we study the masses of hidden charm tetraquark systems (, and ) using a linear confinement potential. In this study, we have factorized the four body system into three subsequent two body systems. To remove degeneracy in the S and P wave masses of mesons and tetraquark states, the spin-spin, spin orbit and tensor components of the confined one gluon exchange interactions are employed. In this attempt, we have been able to assign the as pure tetraquark state. and as pure tetraquark states. According to our analysis is an admixture of and tetraquark state. Additionally, we have been able to predict the radiative decay width , leptonic decay width and hadronic decays of tetraquark stat

    hep-phNPA(2020)·7 citations
  3. 03*

    Interplaying mechanisms behind inclusive jet and extraction of jet energy loss distributions

    Y. He (1)🇨🇳 · S. Cao (2)🇺🇸 · W. Chen (1)🇨🇳 · T. Luo (1)🇨🇳 · L.-G. Pang (3 and 4)🇺🇸 · X.-N. Wang (1, 3 and 4) ((1) Central China Normal University, (2) Wayne State University, (3) University of California, Berkeley, (4) Lawrence Berkeley National Laboratory)🇨🇳

    The observed inclusive jet suppression in heavy-ion collisions at LHC has a very weak dependence over a large range of = 50-1000 GeV and is almost independent of the colliding energy, though the initial energy density of the bulk medium has increased from = 2.76 to 5.02 TeV by about 20%. This interesting phenomenon is investigated in the linear Boltzmann transport (LBT) model for jet propagation in an event-by-event 3+1D hydro background. We show that the dependence of jet is determined by the initial spectrum in collisions and dependence of jet energy loss. Furthermore, jet energy loss distributions for inclusive jet and jet at both LHC energies are extracted directly from experimental data through the state-of-art Bayesian analysis. The averaged jet energy loss has a weak dependence and the scaled jet energy loss distributions have a large width, both of which are consistent with the LBT simulations and indicate that jet quenching is caused by only a few out-of-cone jet medium scatterings.

    hep-phnucl-thNPA(2021)·1 citation
  4. 04*

    Charm decays

    Ulrich Nierste🇩🇪

    I discuss hadronic decays of mesons with emphasis on the recent discovery of charm CP violation in decays. The measured difference of two direct CP asymmetries exceeds the SM prediction by a factor of 7. A possible explanation is an enhancement of the penguin amplitude entering by QCD effects which are not understood yet. Alternatively, could be dominated by contributions from new physics. In order to distinguish these two hypotheses further CP asymmetries should be measured. To this end CP asymmetries resulting from the interference of two tree-level amplitudes auch as or are especially interesting.

    hep-phPoS(2020)·8 citations
  5. 05*

    Jet quenching parameters in strongly coupled anisotropic plasmas in the presence of magnetic fields

    Romulo Rougemont (Rio de Janeiro State U.)🇧🇷

    I use the holographic gauge/gravity duality to systematically calculate the jet quenching parameters in strongly coupled anisotropic plasmas in the presence of external magnetic fields. The magnetic field breaks down spatial rotation symmetry from to , leading to the presence of multiple anisotropic jet quenching parameters, which are evaluated here in two quite different holographic settings. One of them corresponds to a top-down deformation of the strongly coupled Super Yang-Mills plasma triggered by an external magnetic field, while the other one is a bottom-up Einstein-Maxwell-Dilaton model of phenomenological relevance for high energy peripheral heavy ion collisions, since it is able to provide a quantitative description of -flavors lattice QCD thermodynamics with physical quark masses at zero and nonzero magnetic fields. I find for both models an overall enhancement of all the anisotropic jet quenching parameters with increasing magnetic fields. Moreover, I also conclude that for both models transverse momentum broadening is larger in transverse directions than in the direction of the magnetic field. Since these conclusions are shown to hold for two rather different holographic setups at finite temperature and magnetic fields, they are suggested as fairly robust features of strongly coupled anisotropic magnetized plasmas.

    hep-phhep-thnucl-thPRD(2020)·19 citations
  6. 06*

    Lepton flavor violating decays of the SM-like Higgs boson , and in a flipped 3-3-1 model

    T. T. Hong🇻🇳 · H. T. Hung🇻🇳 · H. H. Phuong🇻🇳 · L. T. T. Phuong🇻🇳 · L. T. Hue🇻🇳

    In the framework of the flipped 3-3-1 model introduced recently [1], the lepton-flavor-violating (LFV) decay was predicted to have a large branching ratio (Br) close to the recent experimental limit. We will show that the Br of LFV decays of the standard-model-like (SM-like) Higgs boson decays (LFVHD) Br may also be large. Namely, the Br can reach values of , which will reach the upcoming experimental sensitivities. On the other hand, for LFV decays of charged leptons (cLFV) , the branching ratios are well below experimental bounds.

    hep-phPTEP(2020)·14 citations
  7. 07*

    realization of left-right symmetric linear seesaw

    Purushottam Sahu🇮🇳 · Sudhanwa Patra🇮🇳 · Prativa Pritimita🇮🇳

    We explore an -symmetric flavor based left-right symmetric model with linear seesaw mechanism and study the associated neutrino phenomenology. The framework offers the advantage of studying neutrino mass, non-unitarity effects in lepton sector, lepton flavour violation and CP violation. The fermion content of the model includes usual quarks, leptons along with additional sterile fermion per generation while the scalar content includes Higgs doublets and scalar bidoublet. We study analytically as well as numerically the correlation between different model parameters and their dependence on experimentally determined neutrino observables.

    hep-ph9 citations
  8. 08*

    Unification Predictions With or Without Supersymmetry

    Mina Ketan Parida (Siksha O Anusandhan Univ.)🇮🇳 · Riyanka Samantaray (Siksha O Anusandhan Univ.)🇮🇳

    Supersymmetric (SUSY) grand unified theories (GUTs) appear to be best motivated for understanding strong, weak and electromagnetic interactions of nature. We briefly review emergence of new formulas for running fermion masses valid in direct breaking of GUTs. High scale mixing unification of quark and neutrino mixings and existence of theorems on vanishing theoretical uncertainties in GUT predictions are discussed. D-Parity properties of SO(10) representations leading to large number of intermediate breaking models are pointed out. Unification predictions of SUSY SO(10) in the light of neutrino mass, lepton flavor violation, baryogenesis via leptogenesis within gravitino constraint, and proton decay are noted. We further discuss realisation of flavour unification and possibility of fitting all fermion masses through R-Parity and D-Parity conserving left-right symmetric intermediate breaking in SUSY SO(10). In the absence of SUSY two interesting possibilities of minimal grand desert modifications with only one intermediate mass scalar in each case and their applications to dark matter decay through type-I seesaw are briefly noted. Heavy scalar triplet decay leptogenesis through new ansatz for type-II seesaw dominance in non-SUSY SO(10), emergence of new CP asymmetry formulas and model capabilities to explain WIMP dark matter, vacuum stability of the scalar potential and experimentally observed limit on proton lifetime are briefly summarized.

    hep-phhep-exEur.Phys.J.ST(2020)·4 citations
  9. 09*

    The "96 GeV excess'' at the ILC

    T. Biekötter🇩🇪 · M. Chakraborti🇪🇸 · S. Heinemeyer🇪🇸

    The CMS collaboration reported an intriguing \sim 3 sigma (local) excess at 96 GeV in the light Higgs-boson search in the diphoton decay mode. This mass coincides with a \sim 2 sigma (local) excess in the bb final state at LEP. We present the interpretation of this possible signal as the lightest Higgs boson in the 2 Higgs Doublet Model with an additional real Higgs singlet (N2HDM). It is shown that the type II and type IV (flipped) of the N2HDM can perfectly accommodate both excesses simultaneously, while being in agreement with all experimental and theoretical constraints. The excesses are most easily accommodated in the type II N2HDM, which resembles the Yukawa structure of supersymmetric models. We discuss the experimental prospects for constraining our explanation at future colliders, with concrete analyses based on the ILC prospects.

    hep-ph9 citations
  10. 10*

    Higgs-Photon Production at Future Colliders

    F. Arco🇪🇸 · S. Heinemeyer🇪🇸 · C. Schappacher🇩🇪

    For the search for additional Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) as well as for future precision analyses in the Higgs sector a precise knowledge of their production properties is mandatory. We review the evaluation of the cross sections for the neutral Higgs boson production in association with a photon at future colliders in the MSSM with complex parameters (cMSSM). The evaluation is based on a full one-loop calculation of the production mechanism (). The dependence of the lightest Higgs-boson production cross sections on the relevant cMSSM parameters is analyzed numerically. We find relatively small numerical depedences of the production cross sections on the underlying parameters.

    hep-ph1 citation
  11. 12*

    A Dark Matter Interpretation of Excesses in Multiple Direct Detection Experiments

    Noah Kurinsky🇺🇸 · Daniel Baxter🇺🇸 · Yonatan Kahn🇺🇸 · Gordan Krnjaic🇺🇸

    We present a novel unifying interpretation of excess event rates observed in several dark matter direct-detection experiments that utilize single-electron threshold semiconductor detectors. Despite their different locations, exposures, readout techniques, detector composition, and operating depths, these experiments all observe statistically significant excess event rates of 10 Hz/kg. However, none of these persistent excesses has yet been reported as a dark matter signal because individually, each can be attributed to different well-motivated but unmodeled backgrounds, and taken together, they cannot be explained by dark matter particles scattering elastically off detector nuclei or electrons. We show that these results can be reconciled if the semiconductor detectors are seeing a collective inelastic process, consistent with exciting a plasmon. We further show that plasmon excitation could arise in two compelling dark matter scenarios, both of which can explain rates of existing signal excesses in germanium and, at least at the order of magnitude level, across several single-electron threshold detectors. At least one of these scenarios also yields the correct relic density from thermal freeze-out. Both dark matter scenarios motivate a radical rethinking of the standard interpretations of dark matter-electron scattering from recent experiments.

    hep-phastro-ph.COcond-mat.mtrl-scihep-ex+1PRD(2020)·72 citations
  12. 13*

    Verifiable type-II seesaw and dark matter in a gauged model

    Satyabrata Mahapatra🇮🇳 · Nimmala Narendra🇮🇳 · Narendra Sahu🇮🇳

    We propose a gauged extension of the standard model (SM) to explain simultaneously the light neutrino masses and dark matter (DM). The generation of neutrino masses occurs through a variant of type-II seesaw mechanism in which one of the scalar triplets lies at the TeV scale yet have a large dilepton coupling, which paves a path for probing this model at colliders. The gauging of symmetry in a type-II seesaw framework introduces anomalies. Therefore we invoke three right handed neutrinos (i=1,2,3) with charges -4,-4,+5 to cancel the anomalies. We further show that the lightest one among the three right handed neutrinos can be a viable DM candidate. The stability of DM can be owed to a remnant symmetry under which the right handed neutrinos are odd while all other particles are even. We then discuss the constraints on the model parameters from observed DM abundance and the search at direct detection experiments.

    hep-ph12 citations
  13. 14*

    Quantum Effects in Palatini Higgs Inflation

    Mikhail Shaposhnikov🇨🇭 · Andrey Shkerin🇨🇭 · Sebastian Zell🇨🇭

    We study quantum effects in Higgs inflation in the Palatini formulation of gravity, in which the metric and connection are treated as independent variables. We exploit the fact that the cutoff, above which perturbation theory breaks down, is higher than the scale of inflation. Unless new physics above the cutoff leads to unnaturally large corrections, we can directly connect low-energy physics and inflation. On the one hand, the lower bound on the top Yukawa coupling due to collider experiments leads to an upper bound on the non-minimal coupling of the Higgs field to gravity: . On the other hand, the Higgs potential can only support successful inflation if . This leads to a fairly strict upper bound on the top Yukawa coupling of (defined in the -scheme at the energy scale ) and constrains the inflationary prediction for the tensor-to-scalar ratio. Additionally, we compare our findings to metric Higgs inflation.

    hep-phastro-ph.COgr-qchep-thJCAP(2020)·86 citations
  14. 15*

    SMART U(1) Standard Model with Axion, Right handed neutrinos, Two Higgs doublets and U(1) gauge symmetry

    Nobuchika Okada🇺🇸 · Digesh Raut🇺🇸 · Qaisar Shafi🇺🇸

    To address five fundamental shortcomings of the Standard Model (SM) of particle physics and cosmology, we propose a SMART U(1) model which is a extension of the SM. The gauge symmetry is a generalization of the well-known symmetry and is the global Peccie-Quinn (PQ) symmetry. Three right handed neutrinos are added to cancel related anomalies, and they play a crucial role in understanding the observed neutrino oscillations and explaining the observed baryon asymmetry in the universe via leptogenesis. The PQ symmetry helps resolve the strong CP problem and also provides axion as a compelling dark matter (DM) candidate. The gauge symmetry enables us to implement the inflection-point inflation scenario with GeV, where is the value of Hubble parameter during inflation. This allows us to overcome a potential axion domain wall problem as well as the axion isocurvature problem. The SMART U(1) model can be merged with as we briefly show.

    hep-phEPJC(2020)·14 citations
  15. 16*

    Searching for heavy Higgs in supersymmetric final states at the LHC

    Amit Adhikary🇮🇳 · Biplob Bhattacherjee🇮🇳 · Rohini M. Godbole🇮🇳 · Najimuddin Khan🇮🇳 · Suchita Kulkarni🇦🇹

    In this work, we analyse and demonstrate possible strategies to explore extended Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). In particular we concentrate on heavy Higgs decays to electroweakinos. We analyse the Higgs to electroweakino decays in the allowed MSSM parameter space after taking into account 13 TeV LHC searches for supersymmetric particles and phenomenological constraints such as flavour physics, Higgs measurements and dark matter constraints. We explore some novel aspects of these Higgs decays. The final states resulting from Higgs to electroweakino decays will have backgrounds arising from the Standard Model as well as direct electroweakino production at the LHC. We demonstrate explicit kinematical differences between Higgs to electroweakino decays and associated backgrounds. Furthermore, we demonstrate for a few specific example points, optimised analysis search strategies at the high luminosity LHC (HL-LHC) run. Finally, we comment on possible search strategies for heavy Higgs decays to exotic final states, where the lightest chargino is long lived and leads to a disappearing track at the LHC.

    hep-phJHEP(2021)·11 citations
  16. 17*

    Dark Matter bound-state formation at higher order: a non-equilibrium quantum field theory approach

    Tobias Binder🇯🇵 · Burkhard Blobel🇩🇪 · Julia Harz🇩🇪 · Kyohei Mukaida🇩🇪

    The formation of meta-stable dark matter bound states in coannihilating scenarios could efficiently occur through the scattering with a variety of Standard Model bath particles, where light bosons during the electroweak cross over or even massless photons and gluons are exchanged in the t-channel. The amplitudes for those higher-order processes, however, are divergent in the collinear direction of the in- and out-going bath particles if the mediator is massless. To address the issue of collinear divergences, we derive the bound-state formation collision term in the framework of non-equilibrium quantum field theory. The main result is an expression for a more general cross section, which allows to compute higher-order bound-state formation processes inside the primordial plasma background in a comprehensive manner. Based on this result, we show that next-to-leading order contributions, including the bath-particle scattering, are i) collinear finite and ii) generically dominate over the on-shell emission for temperatures larger than the absolute value of the binding energy. Based on a simplified model, we demonstrate that the impact of these new effects on the thermal relic abundance is significant enough to make it worthwhile to study more realistic coannihilation scenarios.

    hep-phhep-thJHEP(2020)·49 citations
  17. 18*

    Genuine NMSSM deviations in the 125 GeV Higgs boson decays

    Conny Beskidt🇩🇪 · Wim de Boer🇩🇪

    In Supersymmetry deviations from the SM signal strengths of the 125 GeV Higgs boson can occur, because of possible SUSY contributions in diagrams with loops, which leads to different deviations in signal strengths for processes with and without loop diagrams. In the Next-to Minimal Supersymmetric Standard Model (NMSSM) additional deviations may occur, because of the mixing with the additional singlet-like Higgs boson and/or additional decays into pairs of light particles, like neutralinos, pseudo-scalar Higgs bosons or singlet-like Higgs bosons. In this paper we study these "genuine" NMSSM deviations in detail to check not only their possible size, but also look for correlations or anti-correlations with respect to other channels in the hope to find specific patterns in the deviations as for the SUSY contributions, which occur predominantly in processes including loops in the diagrams. The whole NMSSM parameter space is sampled in a deterministic way. The novel scanning method is discussed in detail in the Appendix. We found three different regions with "genuine" NMSSM deviations, which are largely independent of the production mode. What was surprising: some regions show negativ correlations between final states with fermions and bosons meaning if the signal strengths for fermions decrease the signal strengths for bosonic final states increase, while other regions show positive correlations. The sign of the correlations is a strong function of the mass difference between the observed 125 GeV Higgs boson and the Higgs singlet, so looking for correlations could give useful hints about the existence and mass of the singlet Higgs boson. The features of these "genuine" NMSSM effects have been investigated in representative benchmark points for each of the three regions where a single effect is dominant. These benchmark points have been detailed in the Appendix.

    hep-ph0 citations
  18. 19*

    Sterile neutrinos and neutrinoless double beta decay in effective field theory

    Wouter Dekens🇺🇸 · Jordy de Vries🇺🇸 · Kaori Fuyuto🇺🇸 · Emanuele Mereghetti🇺🇸 · Guanghui Zhou🇺🇸

    We investigate neutrinoless double beta decay () in the presence of sterile neutrinos with Majorana mass terms. These gauge-singlet fields are allowed to interact with Standard-Model (SM) fields via renormalizable Yukawa couplings as well as higher-dimensional gauge-invariant operators up to dimension seven in the Standard Model Effective Field Theory extended with sterile neutrinos. At the GeV scale, we use Chiral effective field theory involving sterile neutrinos to connect the operators at the level of quarks and gluons to hadronic interactions involving pions and nucleons. This allows us to derive an expression for rates for various isotopes in terms of phase-space factors, hadronic low-energy constants, nuclear matrix elements, the neutrino masses, and the Wilson coefficients of higher-dimensional operators. The needed hadronic low-energy constants and nuclear matrix elements depend on the neutrino masses, for which we obtain interpolation formulae grounded in QCD and chiral perturbation theory that improve existing formulae that are only valid in a small regime of neutrino masses. The resulting framework can be used directly to assess the impact of experiments on scenarios with light sterile neutrinos and should prove useful in global analyses of sterile-neutrino searches. We perform several phenomenological studies of in the presence of sterile neutrinos with and without higher-dimensional operators. We find that non-standard interactions involving sterile neutrinos have a dramatic impact on phenomenology, and next-generation experiments can probe such interactions up to scales of TeV.

    hep-phnucl-exnucl-thJHEP(2020)·116 citations
  19. 20*

    Beta decays as sensitive probes of lepton flavor universality

    Andreas Crivellin🇨🇭 · Martin Hoferichter🇺🇸

    Nuclear decays as well as the decay of the neutron are well-established low-energy probes of physics beyond the Standard Model (SM). In particular, with the axial-vector coupling of the nucleon determined from lattice QCD, the comparison between experiment and SM prediction is commonly used to derive constraints on right-handed currents. Further, in addition to the CKM element from kaon decays, from decays is a critical input for the test of CKM unitarity. Here, we point out that the available information on decays can be re-interpreted as a stringent test of lepton flavor universality (LFU). In fact, we find that the ratio of from kaon decays over from decays (assuming CKM unitarity) is extremely sensitive to LFU violation (LFUV) in -- couplings thanks to a CKM enhancement by . From this perspective, recent hints for the violation of CKM unitarity can be viewed as further evidence for LFUV, fitting into the existing picture exhibited by semi-leptonic decays and the anomalous magnetic moments of muon and electron. Finally, we comment on the future sensitivity that can be reached with this LFU violating observable and discuss complementary probes of LFU that may reach a similar level of precision, such as at the PEN and PiENu experiments or even direct measurements of at an FCC-ee.

    hep-phhep-exhep-latnucl-ex+1PRL(2020)·120 citations
  20. 21*

    New constraints on the origin of medium-energy neutrinos observed by IceCube

    Antonio Capanema🇧🇷 · Arman Esmaili🇧🇷 · Kohta Murase🇺🇸

    The recent IceCube publication claims the observation of cosmic neutrinos with energies down to TeV, reinforcing the growing evidence that the neutrino flux in the 10-100 TeV range is unexpectedly large. Any conceivable source of these neutrinos must also produce a -ray flux which degrades in energy en route to the Earth and contributes to the extragalactic -ray background measured by the Fermi satellite. In a quantitative multimessenger analysis, featuring minimalistic assumptions, we find a tension in the data, reaching for cosmic neutrinos extended down to TeV, interpreted as evidence for a population of hidden cosmic-ray accelerators.

    hep-phastro-ph.HEPRD(2020)·60 citations
  21. 22*

    Holographic vector meson melting in a thermal gravity-dilaton background related to QCD

    Rico Zöllner🇩🇪 · Burkhard Kampfer🇩🇪

    A holographic model of probe vector mesons (quarkonia) is presented, where the dynamical gravity-dilaton background is adjusted to the thermodynamics of 2 +1 flavor QCD with physical quark masses. The vector meson action is modified to account for various quark masses. We focus on the , and meson melting in agreement with hadron phenomenology in heavy-ion collisions at LHC, that is the formation of hadrons at the observed freeze-out temperature of 155 MeV.

    hep-phhep-thEur.Phys.J.ST(2020)·7 citations
  22. 23*

    Cosmology and prospects for sub-MeV dark matter in electron recoil experiments

    Benjamin V. Lehmann🇺🇸 · Stefano Profumo🇺🇸

    Dark matter is poorly constrained by direct detection experiments at masses below 1 MeV. This is an important target for the next generation of experiments, and several methods have been proposed to probe this mass range. One class of such experiments will search for dark matter--electron recoils. However, simplified models with new light degrees of freedom coupled to electrons face significant pressure from cosmology, and the extent of these restrictions more generally is poorly understood. Here, we perform a systematic study of cosmological constraints on models with a heavy mediator in the context of an effective field theory. We include constraints from (i) disruption of primordial nucleosynthesis, (ii) overproduction of dark matter, and (iii) the effective number of neutrino species at recombination. We demonstrate the implications of our results for proposed electron recoil experiments, and highlight scenarios which may be amenable to direct detection.

    hep-phPRD(2020)·17 citations
  23. 24*

    The gluon condensation effect in the cosmic hadron spectra

    W. Zhu🇨🇳 · P. Liu🇨🇳 · J.H. Ruan🇨🇳 · R.Q. Wang🇨🇳 · F. Wang🇺🇸

    Hardening of cosmic proton- and nuclei-spectra is explained by using the gluon condensation (GC) model, which states that a large amount of gluons in proton may condense near the high energy threshold. The results present the GC-effect as common origin of a series of anomalous astrophysical phenomena including the broken power-law in gamma-ray spectra, the excess in positron- and electron-spectra and hardening of proton- and nuclei-spectra.

    astro-ph.HEhep-phnucl-thJCAP(2020)·5 citations
  24. 25*

    Measurements of in modified gravity theories: The role of lensed quasars in the late-time Universe

    Rocco D'Agostino🇮🇹 · Rafael C. Nunes🇧🇷

    In this work, we obtain measurements of the Hubble constant in the context of modified gravity theories. We set up our theoretical framework by considering viable cosmological and models, and we analyzed them through the use of geometrical data sets obtained in a model-independent way, namely, gravitationally lensed quasars with measured time delays, standard clocks from cosmic chronometers, and standard candles from the Pantheon Supernovae Ia sample. We find km s Mpc and km s Mpc for the and models, respectively. Our results represent 1.9\% and 1.8\% measurements of the Hubble constant, which are fully consistent with the local estimate of by the Hubble Space Telescope. We do not find significant departures from general relativity, as our study shows that the characteristic parameters of the extensions of gravity beyond general relativity are compatible with the CDM cosmology. Moreover, within the standard cosmological framework, our full joint analysis suggests that it is possible to measure the dark energy equation of state parameter at 1.2\% accuracy, although we find no statistical evidence for deviations from the cosmological constant case.

    astro-ph.COgr-qchep-phPRD(2020)·93 citations
  25. 26*

    On the light-front wave functions of quarkonia

    Pieter Maris🇺🇸 · Shaoyang Jia🇺🇸 · Meijian Li🇺🇸 · Yang Li🇺🇸 · Shuo Tang🇺🇸 · James P. Vary🇺🇸

    The light-front wave functions of hadrons allow us to calculate a wide range of physical observables; however, the wave functions themselves cannot be measured. We discuss recent results for quarkonia obtained in basis light-front quantization using an effective Hamiltonian with a confining model in both the transverse and longitudinal directions and with explicit one-gluon exchange. In particular, we focus on the numerical convergence of the basis expansion, as well as the asymptotic behavior of the light-front wave functions. We also illustrate that, for mesons with unequal quark masses, the maxima of the light-front wave functions depend in a non-trivial way on the valence quark-mass difference.

    nucl-thhep-phPoS(2020)·4 citations
  26. 27*

    Discovery of a new supernova remnant G21.8-3.0

    X. Y. Gao🇨🇳 · P. Reich🇩🇪 · W. Reich🇩🇪 · L. G. Hou🇨🇳 · J. L. Han🇨🇳

    Sensitive radio continuum surveys of the Galactic plane are ideal for discovering new supernova remnants (SNRs). From the Sino-German {\lambda}6 cm polarisation survey of the Galactic plane, an extended shell-like structure has been found at l = 21.8 degree, b = -3.0 degree, which has a size of about 1 degree. New observations were made with the Effelsberg 100-m radio telescope at {\lambda}11 cm to estimate the source spectrum together with the Urumqi {\lambda}6 cm and the Effelsberg {\lambda}21 cm data. The spectral index of G21.8-3.0 was found to be {\alpha} = -0.72 {\pm} 0.16. Polarised emission was mostly detected in the eastern half of G21.8-3.0 at both {\lambda}6 cm and {\lambda}11 cm. These properties, together with the H{\alpha} filament along its northern periphery and the lack of infrared emission, indicate that the emission is non-thermal as is usual in shell-type SNRs.

    astro-ph.GAhep-phMNRAS(2020)·8 citations
  27. 28*

    Studying the parton content of the proton with deep learning models

    Juan M Cruz-Martinez🇮🇹 · Stefano Carrazza🇮🇹 · Roy Stegeman🇮🇹

    Parton Distribution Functions (PDFs) model the parton content of the proton. Among the many collaborations which focus on PDF determination, NNPDF pioneered the use of Neural Networks to model the probability of finding partons (quarks and gluons) inside the proton with a given energy and momentum. In this proceedings we make use of state of the art techniques to modernize the NNPDF methodology and study different models and optimizers in order to improve the quality of the PDF: improving both the quality and efficiency of the fits. We also present the evolutionary_keras library, a Keras implementation of the Evolutionary Algorithms used by NNPDF.

    physics.comp-phhep-phPoS(2020)·3 citations
  28. 29*

    Multi-stage evolution of heavy quarks in the quark-gluon plasma

    G. Vujanovic🇺🇸 · A. Angerami🇺🇸 · S. A. Bass🇺🇸 · S. Cao🇺🇸 · Y. Chen🇺🇸 · J. Coleman🇺🇸 · L. Cunqueiro🇺🇸 · T. Dai🇺🇸 · L. Du🇺🇸 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 · D. Everett🇺🇸 and 38 other authors

    The interaction of heavy flavor with the quark-gluon plasma (QGP) in relativistic heavy-ion collisions is studied using JETSCAPE, a publicly available software package containing a framework for Monte Carlo event generators. Multi-stage (and multi-model) evolution of heavy quarks within JETSCAPE provides a cohesive description of heavy flavor quenching inside the QGP. As the parton shower develops, a model becomes active as soon as its kinematic region of validity is reached. Two combinations of heavy-flavor energy-loss models are explored within a realistic QGP medium, using parameters which were tuned to describe {\it light-flavor} partonic energy-loss.

    nucl-thhep-phNPA(2021)·8 citations
  29. 30*

    Non-perturbative definition of the QCD energy-momentum tensor on the lattice

    Mattia Dalla Brida🇮🇹 · Leonardo Giusti🇮🇹 · Michele Pepe🇮🇹

    We present a strategy to define non-perturbatively the energy-momentum tensor in Quantum Chromodynamics (QCD) which satisfies the appropriate Ward identities and has the right trace anomaly. The tensor is defined by regularizing the theory on a lattice, and by fixing its renormalization constants non-perturbatively by suitable Ward identities associated to the Poincare' invariance of the continuum theory. The latter are derived in thermal QCD with a non-zero imaginary chemical potential formulated in a moving reference frame. A renormalization group analysis leads to simple renormalization-group-invariant definitions of the gluonic and fermionic contributions to either the singlet or the non-singlet components of the tensor, and therefore of their form factors among physical states. The lattice discussion focuses on the Wilson discretization of quark fields but the strategy is general. Specific to that case, we also carry out the analysis for the on-shell O(a)-improvement of the energy-momentum tensor. The renormalization and improvement programs profit from the fact that, as shown here, the thermal theory enjoys de-facto automatic O(a)-improvement at finite temperature. The validity of the proposal is scrutinized analytically by a study to 1-loop order in lattice perturbation theory with shifted and twisted (for quarks only) boundary conditions. The latter provides also additional useful insight for a precise non-perturbative calculation of the renormalization constants. The strategy proposed here is accessible to Monte Carlo computations, and in this sense it provides a practical way to define non-perturbatively the energy-momentum tensor in QCD.

    hep-lathep-phhep-thnucl-thJHEP(2020)·37 citations
  30. 31*

    Model-independent determination of the nucleon charge radius from lattice QCD

    Constantia Alexandrou🇨🇾 · Kyriakos Hadjiyiannakou🇨🇾 · Giannis Koutsou🇨🇾 · Konstantin Ottnad🇩🇪 · Marcus Petschlies🇩🇪

    Lattice QCD calculations of nucleon form factors are restricted to discrete values of the Euclidean four-momentum transfer. Therefore, the extraction of radii typically relies on parametrizing and fitting the lattice QCD data to obtain its slope close to zero momentum transfer. We investigate a new method, which allows to compute the nucleon radius directly from existing lattice QCD data, without assuming a functional form for the momentum dependence of the underlying form factor. The method is illustrated for the case of the isovector mean square charge radius of the nucleon and the quark-connected contributions to and for the proton and neutron, respectively. Computations are performed using a single gauge ensemble with maximally twisted mass clover-improved fermions at physical quark mass and a lattice spacing of .

    hep-lathep-phnucl-exnucl-thPRD(2020)·33 citations
  31. 32*

    Effects of initial state fluctuations on the mean transverse momentum

    Fernando G. Gardim🇧🇷 · Giuliano Giacalone🇫🇷 · Matthew Luzum🇧🇷 · Jean-Yves Ollitrault🇫🇷

    We show that in ideal hydrodynamic simulations of heavy-ion collisions, initial state fluctuations result in an increase of the mean transverse momentum of outgoing hadrons, . Specifically, is larger by a few percent if realistic fluctuations are implemented than with smooth initial conditions, the multiplicity and impact parameter being kept fixed. We show that result can be traced back to the fact that for a given total entropy, the initial energy contained in the fluid is larger if the density profile is bumpy. We discuss the implication of these results for the extraction of the equation of state of QCD from experimental data.

    nucl-thhep-phnucl-exNPA(2021)·26 citations
  32. 33*

    Jet quenching in a multi-stage Monte Carlo approach

    A. Kumar🇺🇸 · A. Angerami🇺🇸 · S. A. Bass🇺🇸 · S. Cao🇺🇸 · Y. Chen🇺🇸 · J. Coleman🇺🇸 · L. Cunqueiro🇺🇸 · T. Dai🇺🇸 · L. Du🇺🇸 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 · D. Everett🇺🇸 and 38 other authors

    We present a jet quenching model within a unified multi-stage framework and demonstrate for the first time a simultaneous description of leading hadrons, inclusive jets, and elliptic flow observables which spans multiple centralities and collision energies. This highlights one of the major successes of the JETSCAPE framework in providing a tool for setting up an effective parton evolution that includes a high-virtuality radiation dominated energy loss phase (MATTER), followed by a low-virtuality scattering dominated (LBT) energy loss phase. Measurements of jet and charged-hadron set strong constraints on the jet quenching model. Jet-medium response is also included through a weakly-coupled transport description.

    nucl-thhep-phnucl-exNPA(2021)·11 citations
  33. 34*

    Study of the coupling at the ILC

    Yumi Aoki🇯🇵 · Keisuke Fujii🇯🇵 · Sunghoon Jung🇰🇷 · Junghwan Lee🇰🇷 · Junping Tian🇯🇵 · Hiroshi Yokoya🇰🇷

    We study the coupling, which is a loop induced coupling in the Standard Model (SM), to probe new physics. In a global fit based on the SM Effective Field Theory, measurement of the SM coupling can provide a very useful constraint, in particular for the precise determination of and couplings. At the International Linear Collider (ILC), there are two direct ways to study the coupling: one is to measure the branching ratio of the decay and the other to measure the cross section for the process. We have performed a full simulation study of the process at the 250 GeV ILC, assuming 2 ab data collected by the International Large Detector (ILD). The expected 1 bound on the effective coupling () combining measurements of the cross section for followed by and the branching ratio is . The expected significance for the signal cross section in the fully hadronic channel is 0.09 for beam polarizations of .

    hep-exhep-ph3 citations
  34. 35*

    Quark cores in extensions of the MIT Bag model

    Salil Joshi🇮🇳 · Sovan Sau🇮🇳 · Soma Sanyal🇮🇳

    Recent observations of massive pulsars having masses of the order of two solar mass pose a new challenge for compact objects such as hybrid stars and neutron stars. Extensions of the bag model and the Nambu-Jona-Lasino model have been used to model these stars to get higher mass stars. Quark matter has been predicted in the cores of these massive stars. In this work we show that an extension of the bag model, with a chemical potential dependent bag parameter can lead to an isentropic phase transition in the core of the neutron star. Our model shows that an EoS having all three quarks , and would lead to massive stars with stable quark matter. We find that the mass of the stars not only depends on the bag constant but also on the mass of the strange quark. The mass - radius ratio which determines the redshift values on the surface, indicates that it is possible to obtain stable self bound strange quark matter stars with reasonable values of the bag pressure which correspond to the recent observations of large mass stars.

    nucl-thhep-phJHEAp(2021)·21 citations
  35. 36*

    Testing ER=EPR

    De-Chang Dai🇨🇳 · Djordje Minic🇺🇸 · Dejan Stojkovic🇺🇸 · Changbo Fu🇨🇳

    We discuss a few tests of the ER=EPR proposal. We consider certain conceptual issues as well as explicit physical examples that could be experimentally realized. In particular, we discuss the role of the Bell bounds, the large N limit, as well as the consistency of certain theoretical assumptions underlying the ER=EPR proposal. As explicit tests of the ER=EPR proposal we consider limits coming from the entropy-energy relation and certain limits coming from measurements of the speed of light as well as measurements of effective weights of entangled states. We also discuss various caveats of such experimental tests of the ER=EPR proposal.

    hep-thgr-qchep-phPRD(2020)·28 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.