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Nuclear Theory·nucl-th

Tuesday·October 12, 2021

19 papers—7 primary·12 cross-listed

All19Primary7Cross-lists12
  1. 01

    [Submitted on 9 Oct 2021]

    Singly heavy baryons in nuclear matter from an SU(3) chiral soliton model

    Ho-Yeon Won🇰🇷 · Ulugbek Yakhshiev🇰🇷 · Hyun-Chul Kim🇰🇷

    We investigate how the masses of the singly heavy baryons undergo changes in nuclear matter, based on a medium-modified SU(3) chiral soliton model. Having explained the bulk properties of nuclear matter, we discuss the masses of the singly heavy baryons in nuclear matter. We generalize the vector-meson Lagrangian including the heavy-meson soliton interaction. The mass spectrum of the singly heavy baryon are obtained with the effects of explicit SU(3) symmetry breaking considered as a perturbation. The results show that the mass of the singly heavy baryon mass in nuclear medium is rather sensitive to the medium modifications of the heavy meson mass.

    Comments:
    10 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2110.04561 [pdf]
    J.Phys.G(2022)·3 citations
  2. 02

    [Submitted on 9 Oct 2021]

    Relativistic second-order dissipative hydrodynamics from Zubarev's non-equilibrium statistical operator

    Arus Harutyunyan🇦🇲 · Armen Sedrakian🇩🇪 · Dirk H. Rischke🇩🇪

    We present a new derivation of relativistic second-order dissipative hydrodynamics for quantum systems using Zubarev's non-equilibrium statistical-operator formalism. This is achieved by a systematic expansion of the energy-momentum tensor and the charge current to second order in deviations from equilibrium. As a concrete example, we obtain the relaxation equations for the shear-stress tensor, the bulk-viscous pressure, and the charge-diffusion currents required to close the set of equations of motion for relativistic second-order dissipative hydrodynamics. We also identify new transport coefficients which describe the relaxation of dissipative processes to second order and express them in terms of equilibrium correlation functions, thus establishing new Kubo-type formulas for second-order transport coefficients.

    Comments:
    54 pages
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th)
    arXiv:
    2110.04595 [pdf]
    Annals Phys.(2022)·28 citations
  3. 03

    [Submitted on 10 Oct 2021]

    Complementary Two-Particle Correlation Observables for Relativistic Nuclear Collisions

    Mary Cody🇺🇸 · Sean Gavin🇺🇸 · Brendan Koch🇺🇸 · Mark Kocherovsky🇺🇸 · Zoulfekar Mazloum🇺🇸 · George Moschelli🇺🇸

    Two-particle correlations are a widely used tool for studying relativistic nuclear collisions. Multiplicity fluctuations comparing charge and particle species have been studied as a possible signal for Quark-Gluon Plasma (QGP) and the QCD critical point. These fluctuation studies all make use of particle variances which can be shown to originate with a two-particle correlation function. Momentum correlations and covariances of momentum fluctuations, which arise from the same correlation function, have also been used to extract properties of the nuclear collision medium such as the shear viscosity to entropy density ratio, the shear relaxation time, and temperature fluctuations. Searches for critical fluctuations are also done with these correlation observables. We derive a mathematical relationship between several number and momentum density correlation observables and outline the different physics mechanisms often ascribed to each. This set of observables also contains a new multiplicity-momentum correlation. Our mathematical relation can be used as a validation tool for measurements, as a method for interpreting the relative contributions of different physics mechanisms on correlation observables, and as a test for theoretical and phenomenological models to simultaneously explain all observables. We compare an independent source model to simulated events from PYTHIA for all observables in the set.

    Comments:
    18 pages, 10 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2110.04884 [pdf]
    PRC(2023)·9 citations
  4. 04

    [Submitted on 11 Oct 2021]

    Single-particle decomposition of nuclear surface diffuseness

    Wataru Horiuchi

    Nuclear surface diffuseness reflects spectroscopic information near the Fermi level. I propose a way to decompose the surface diffuseness into single-particle (s.p.) contributions in a quantitative way. Systematic behavior of the surface diffuseness of neutron-rich even-even O, Ca, Ni, Sn, and Pb isotopes is analyzed with a phenomenological mean-field approach. The role of the s.p. wave functions near the Fermi level is explored: The nodeless s.p. orbits form a sharp nuclear surface, while the nodal s.p. orbits contribute to diffusing the nuclear surface.

    Comments:
    18 pages, 14 figures, to appear in Prog. Theor. Exp. Phys
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2110.04982 [pdf]
    PTEP(2021)·17 citations
  5. 05

    [Submitted on 8 Oct 2021]

    Hot Neutron Star Matter and Proto-Neutron Stars

    D. Farrell (SDSU)🇺🇸 · A. Alp (SDSU)🇺🇸 · W. Spinella (IVC)🇺🇸 · F. Weber (SDSU, UCSD)🇺🇸 · G. Malfatti (U. La Plata)🇦🇷 · M. G. Orsaria (U. La Plata)🇦🇷 · I. F. Ranea-Sandoval (U. La Plata, CONICET)🇦🇷

    In this chapter, we investigate the structure and composition of hot neutron star matter and proto-neutron stars. Such objects are made of baryonic matter that is several times denser than atomic nuclei and tens of thousands times hotter than the matter in the core of our Sun. The relativistic finite-temperature Green function formalism is used to formulate the expressions that determine the properties of such matter in the framework of the density-dependent mean field approach. Three different sets of nuclear parametrizations are used to solve the many-body equations and to determine the models for the equation of state of ultra-hot and dense stellar matter. The meson-baryon coupling scheme and the role of the \{Delta}(1232) baryon in proto-neutron star matter are investigated in great detail. In addition, using the non-local three-flavor Nambu-Jona-Lasinio model to describe quark matter, the hadron-quark composition of dense baryonic matter at zero temperature is discussed briefly. General relativistic models of non-rotating as well as rotating proto-neutron stars are presented in part two of our study.

    Comments:
    62 pages, 34 figures; book chapter to appear in "New Phenomena and New States of Matter in the Universe: From Quarks to Cosmos", World Scientific, eds. Cesar Augusto Zen Vasconcellos, Peter Otto Hess, and Thomas Boller; ISBN 978-981-122-090-6
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2110.05189 [pdf]
    2 citations
  6. 06

    [Submitted on 11 Oct 2021]

    Nonperturbative two-pion exchange contributions to the nucleon-nucleon interaction in covariant baryon chiral perturbation theory

    Chun-Xuan Wang🇨🇳 · Jun-Xu Lu🇨🇳 · Yang Xiao🇨🇳 · Li-Sheng Geng🇨🇳

    We calculate the nonperturbative two-pion exchange (TPE) contributions to the interaction in covariant baryon chiral perturbation theory. We study how the nonperturbative resummation affects the phase shifts for partial waves with and . No significant differences are observed between the nonperturbative phase shifts and perturbative ones for most partial waves except for , for which the nonperturbative resummation greatly improves the description of the phase shifts. However, a significant cutoff dependence is found for this partial wave and a reasonable description of the phase shifts can only be obtained with a particular cutoff. Furthermore, we compare the so-obtained nonperturbative phase shifts with those obtained in the heavy baryon chiral perturbation theory. We show that the contributions from relativistic nonperturbative TPE are more moderate than those from the nonrelativistic TPE obtained in the dimensional regularization scheme. A proper convergence pattern is observed for most of the partial waves studied except for , , and , for which the subleading TPE contributions are a bit strong. We find that for and partial waves, the OPE alone can already describe the phase shifts reasonably well.

    Comments:
    17 pages, 11 figures, to appear in Physical Review C
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2110.05278 [pdf]
    PRC(2022)·14 citations
  7. 07

    [Submitted on 11 Oct 2021]

    Elastic proton scattering off non-zero spin nuclei

    Matteo Vorabbi · Michael Gennari · Paolo Finelli · Carlotta Giusti · Petr Navrátil · Ruprecht Machleidt

    In recent years, we constructed a microscopic optical potential (OP) for elastic nucleon-nucleus () scattering using modern approaches based on chiral theories for the nucleon-nucleon () interaction. The OP was derived at first order of the spectator expansion in Watson multiple scattering theory and its final expression was a folding integral between the matrix and the nuclear density of the target. Two- and three-body forces are consistently included both in the target and in the projectile description. The purpose of this work is to apply our microscopic OP to nuclei characterized by a ground state of spin-parity quantum numbers . We extended our formalism to include the spin of the target nucleus. The full amplitudes of the reaction matrix are retained in the calculations starting from two- and three-body chiral forces. We show a remarkable agreement with experimental data for the available observables and, simultaneously, provide reliable estimates for the theoretical uncertainties. This work paves the way toward a full microscopic approach to inelastic scattering, showing that the derivation of optical potentials between states with is completely under control.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2110.05455 [pdf]
    PRC(2022)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE