PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·January 30, 2020

10 papers—5 primary·5 cross-listed

All10Primary5Cross-lists5
  1. 01

    Hyperon-nucleon three-body forces and strangeness in neutron stars

    Dominik Gerstung🇩🇪 · Norbert Kaiser🇩🇪 · Wolfram Weise🇩🇪

    Three-body forces acting on a hyperon in a nuclear medium are investigated, with special focus on the so-called hyperon puzzle in neutron stars. The hyperon-nucleon two-body interaction deduced from SU(3) chiral effective field theory is employed at next-to-leading order. Hyperon-nucleon three-body forces are approximated using saturation by decuplet baryons and are transcribed to density-dependent effective two-body interactions. These together are taken as input in a Brueckner-Bethe-Goldstone equation with explicit treatment of the and coupled channels. Single-particle potentials of a hyperon in symmetric nuclear matter and neutron matter are calculated. With parameters of the three-body force constrained by hypernuclear phenomenology, extrapolations to high baryon density are performed. By comparison of the and neutron chemical potentials at densities characteristic of the core of neutron stars it is found that the combined repulsive effects of two- and three-body correlations makes the appearance of hyperons in neutron stars energetically unfavourable, thus offering a possible solution to a longstanding question.

    nucl-thEPJA(2020)·133 citations
  2. 02

    Cross-conductivity: novel transport coefficients to constrain the hadronic degrees of freedom of nuclear matter

    Jean-Bernard Rose🇩🇪 · Moritz Greif🇩🇪 · Jan Hammelmann🇩🇪 · Jan A. Fotakis🇩🇪 · Gabriel S. Denicol🇧🇷 · Hannah Elfner🇩🇪 · Carsten Greiner🇩🇪

    In general, the constituents of the bulk matter produced in heavy-ion collisions carry, besides electric charge, multiple other conserved quantum numbers like baryon number and strangeness. Therefore, an electric field will not only generate an electric current but, at the same time, also currents in baryon number and strangeness. We propose that the impact of the electric field on these conserved currents should be characterized by additional transport coefficients, which we call cross-conductivities. In this paper, we introduce and present a calculation of these cross-conductivities from the Green-Kubo formalism within the transport code SMASH for different chemical compositions of hadron resonance gases. We find that the coefficients underlie an ordering in the active degrees of freedom and that thus the chemical composition of the system plays a crucial role. Further, we argue that in future comparisons of lattice QCD calculations with these findings, one could constrain which degrees of freedom and their corresponding charge properties are relevant for the QCD dynamics of the system.

    nucl-thhep-phPRD(2020)·29 citations
  3. 03

    Number of constituent quark scaling of elliptic flows in high multiplicity p-Pb collisions at 5.02 TeV

    Wenbin Zhao🇨🇳 · Che Ming Ko🇺🇸 · Yu-Xin Liu🇨🇳 · Guang-You Qin🇨🇳 · Huichao Song🇨🇳

    We briefly summarize our recent study on the number of constituent quark (NCQ) scaling of hadron elliptic flows in high multiplicity p-Pb collisions at 5.02 TeV. With the inclusion of hadron production via the quark coalescence model at intermediate , the viscous hydrodynamics at low , and jet fragmentation at high , our model provides a nice description of the -spectra and differential elliptic flow of pions, kaons and protons over the range from 0 to 6 GeV. Our results demonstrate that including the quark coalescence is essential for reproducing the observed approximate NCQ scaling of hadron at intermediate in experiments, indicating strongly the existence of partonic degrees of freedom and the formation of quark-gluon plasma in high multiplicity p--Pb collisions at the LHC.

    nucl-thhep-phnucl-exNPA(2021)·2 citations
  4. 04

    Hydrodynamic attractors for Gubser flow

    Ashutosh Dash🇮🇳 · Victor Roy🇮🇳

    The Boltzmann equation is solved in the relaxation time approximation using a hierarchy of angular moments of the distribution function. Our solution is obtained for an azimuthally symmetric radially expanding boost-invariant conformal system that is undergoing Gubser flow. The solution of moments that we get after truncating the infinite set of equations at various orders is compared to the exact kinetic solution. The dynamics of transition is described by the presence of fixed points which describes the evolution of the system from an early time collisionless free streaming to the hydrodynamic regime at intermediate times and back to free streaming at late times. The attractor solution is found for various orders of moments as an interpolation between these fixed points. The relation of moments to various approximations of relativistic viscous hydrodynamics is investigated.

    nucl-thPLB(2020)·43 citations
  5. 05

    Evolution of quasiperiodic structures in non-ideal hydrodynamic description of phase transitions

    D. N. Voskresensky🇷🇺

    Various phase transitions could have taken place in the early Universe, and may occur in the course of heavy-ion collisions and supernova explosions, in proto-neutron stars, cold compact stars, and in the condensed matter at terrestrial conditions. Most generally, the dynamics of the density and temperature at first- and second-order phase transitions can be described with the help of the equations of non-ideal hydrodynamics. In the given work some novel solutions are found describing the evolution of quasiperiodic structures that are formed in the course of the phase transitions. Although this consideration is very general, particular examples of quark-hadron and nuclear liquid-gas first-order phase transitions to the uniform k_0=0 state and pion condensate second-order phase transition to non-uniform k_0\neq 0 state in dense baryon matter are considered.

    nucl-thhep-phUniverse(2020)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE