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Nuclear Theory·nucl-th

Thursday·March 26, 2020

8 papers—1 primary·7 cross-listed

All8Primary1Cross-lists7
  1. 02

    Inverse magnetic catalysis -- how much do we know about?

    Aritra Bandyopadhyay🇨🇳 · Ricardo L S Farias🇧🇷

    Some of the advances made in the literature to understand the phase transitions of quark matter in the presence of strong magnetic field and finite temperature (zero quark chemical potential) are reviewed. We start by discussing the physics behind the Magnetic catalysis (MC) at zero/finite temperature and then focus on the lattice predictions for inverse magnetic catalysis (IMC) at high temperature and strong magnetic fields. Possible explanations for the IMC are covered as well. Finally, we discuss recent efforts to modify QCD (quantum chromodynamics) effective models in order to reproduce the IMC observed on the lattice simulations. We emphasize the fact that applying thermo-magnetic effects on the coupling constant of the NJL model significantly improve the effectiveness of the NJL model to obtain a reasonable physical description of hot and magnetized quark matter being in agreement with lattice results.

    ↳ hep-phhep-latnucl-thEur.Phys.J.ST(2021)·55 citations
  2. 03

    CVE for photons: black-hole vs. flat-space derivation

    G. Yu. Prokhorov🇷🇺 · O. V. Teryaev🇷🇺 · V. I. Zakharov🇷🇺

    The chiral vortical effect (CVE) was derived first for non-interacting massless fermions. Recently, an alternative derivation of the CVE was suggested which relates it to the radiation from the horizon of a rotating black hole. We attempt to generalize the latter derivation to the case of photons and encounter a crucial factor of two difference between the two ways of visualizing the CVE. Reservations and possible explanations are briefly discussed.

    ↳ hep-thgr-qcnucl-thPRD(2020)·24 citations
  3. 04

    Second-order quark number susceptibility of deconfined QCD matter in the presence of a magnetic field

    Bithika Karmakar🇮🇳 · Najmul Haque🇮🇳 · Munshi G Mustafa🇮🇳

    Considering the strong field approximation we compute the hard thermal loop pressure at finite temperature and chemical potential of hot and dense deconfined QCD matter in lowest Landau level in one-loop order. We consider the anisotropic pressure in the presence of the strong magnetic field i.e., longitudinal and transverse pressure along parallel and perpendicular to the magnetic field direction. As a first effort, we compute and discuss the anisotropic quark number susceptibility of deconfined QCD matter in lowest Landau level. The longitudinal quark number susceptibility is found to increase with the temperature whereas the transverse one decreases with the temperature. We also compute the quark number susceptibility in the weak field approximation. We find that the thermomagnetic correction to the quark number susceptibility is very marginal in the weak field approximation.

    ↳ hep-phhep-latnucl-thPRD(2020)·14 citations
  4. 05

    Joint lattice QCD - dispersion theory analysis confirms the quark-mixing top-row unitarity deficit

    Chien-Yeah Seng🇩🇪 · Xu Feng🇨🇳 · Mikhail Gorchtein🇩🇪 · Lu-Chang Jin🇺🇸

    Recently, the first ever lattice computation of the -box radiative correction to the rate of the semileptonic pion decay allowed for a reduction of the theory uncertainty of that rate by a factor of . A recent dispersion evaluation of the -box correction on the neutron also led to a significant reduction of the theory uncertainty, but shifted the value of extracted from the neutron and superallowed nuclear decay, resulting in a deficit of the CKM unitarity in the top row. A direct lattice computation of the -box correction for the neutron decay would provide an independent cross-check for this result but is very challenging. Before those challenges are overcome, we propose a hybrid analysis, converting the lattice calculation on the pion to that on the neutron by a combination of dispersion theory and phenomenological input. The new prediction for the universal radiative correction to free and bound neutron -decay reads , in excellent agreement with the dispersion theory result . Combining with other relevant information, the top-row CKM unitarity deficit persists.

    ↳ hep-phhep-exhep-latnucl-ex+1PRD(2020)·144 citations
  5. 06

    Nonperturbative Flavor Breaking in Topological Susceptibility at Chiral Crossover

    Mamiya Kawaguchi🇨🇳 · Shinya Matsuzaki🇨🇳 · Akio Tomiya🇺🇸

    We demonstrate that the QCD topological susceptibility nonperturbatively gets a significant contribution signaled by flavor-nonuniversal quark condensates at around the pseudo-critical temperature of the chiral crossover. It implies a remarkable flavor breaking in the axial anomaly as well as the QCD theta vacuum in high temperature QCD, which are almost flavor universal in the vacuum. A nontrivial flavor breaking is triggered by nonperturbative thermal loop corrections at around the chiral crossover, which is different from the trivial flavor violation just scaled by the quark mass ratio, observed at asymptotically high temperatures. This critical flavor violation cannot be dictated by the chiral perturbation theory with that lattice QCD usually compares, or the dilute instanton gas approximation based on that its astrophysical implications have conventionally been made. This would give an impact on the thermal history and the cosmological evolution of QCD axion including the estimate of the relic abundance as a dark matter candidate.

    ↳ hep-phastro-ph.COhep-latnucl-thPLB(2021)·8 citations
  6. 07

    Logarithmic Regge Pole

    S. D. Campos (Universidade Federal de São Carlos-CCTS/DFQM)🇧🇷

    This work presents the subtraction procedure and the Regge cut in the logarithmic Regge pole approach. The subtraction mechanism leads to the same asymptotic behavior as previously obtained in the non-subtraction case. The Regge cut, on the other hand, introduces a clear role to the non-leading contributions for the asymptotic behavior of the total cross section. From these results, one introduces some simple parameterization to fit the experimental data for the proton-proton and antiproton-proton total cross section above some minimum value up to the cosmic-ray. The fit parameters obtained are used to present predictions for the -parameter as well as to the elastic slope at high energies.

    ↳ hep-phnucl-th2 citations
  7. 08

    Coherent Elastic Neutrino-Nucleus Scattering with directional detectors

    M. Abdullah🇺🇸 · D. Aristizabal Sierra🇨🇱 · Bhaskar Dutta🇺🇸 · Louis E. Strigari🇺🇸

    We study the sensitivity of detectors with directional sensitivity to coherent elastic neutrino-nucleus scattering (CENS), and how these detectors complement measurements of the nuclear recoil energy. We consider stopped pion and reactor neutrino sources, and use gaseous helium and fluorine as examples of detector material. We generate Standard Model predictions, and compare to scenarios that include new, light vector or scalar mediators. We show that directional detectors can provide valuable additional information in discerning new physics, and we identify prominent spectral features in both the angular and the recoil energy spectrum for light mediators, even for nuclear recoil energy thresholds as high as keV. Combined with energy and timing information, directional information can play an important role in extracting new physics from CENS experiments.

    ↳ hep-phhep-exnucl-exnucl-th+1PRD(2020)·30 citations

Affiliations

first authorsco-authorsvia INSPIRE