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Nuclear Theory·nucl-th

Wednesday·September 13, 2023

11 papers—5 primary·6 cross-listed

All11Primary5Cross-lists6
  1. 01

    [Submitted on 11 Sept 2023]

    Entropy current and entropy production in relativistic spin hydrodynamics

    Francesco Becattini🇮🇹 · Asaad Daher🇵🇱 · Xin-Li Sheng🇮🇹

    We use a first-principle quantum-statistical method to derive the expression of the entropy production rate in relativistic spin hydrodynamics. We show that the entropy current is not uniquely defined and can be changed by means of entropy-gauge transformations, much the same way as the stress-energy tensor and the spin tensor can be changed with pseudo-gauge transformations. We show that the local thermodynamic relations, which are admittedly educated guesses in relativistic spin hydrodynamics inspired by those at global thermodynamic equilibrium, do not hold in general and they are also non-invariant under entropy-gauge transformations. Notwithstanding, we show that the entropy production rate is independent of those transformations and we provide a universally applicable expression, extending that known in literature, from which one can infer the dissipative parts of the energy momentum and spin tensors.

    Comments:
    14 pages with 2 figures. Comments are welcome
    Subjects:
    Nuclear Theory (nucl-th); Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Theory (hep-th)
    arXiv:
    2309.05789 [pdf]
    PLB(2024)·48 citations
  2. 02

    [Submitted on 12 Sept 2023]

    Exploring Short-Range Correlations in Symmetric Nuclei: Insights into Contacts and Entanglement Entropy

    Wei Kou🇨🇳 · Jingxuan Chen🇨🇳 · Xurong Chen🇨🇳

    The Short-Range Correlations between nucleons in nuclei is regarded as a complex system. We investigate the relationship between the orbital entanglement entropy of SRCs in nuclear structures and Tan contact , and find that the orbital entanglement entropies and Tan contacts corresponding to proton-proton SRC pairs and neutron-proton SRC pairs in nuclei demonstrate a scaling relation. More specifically, the proportionality of entanglement entropy between proton-proton pairs and neutron-proton pairs is directly related to the ratio of nuclear contacts within the atomic nucleus, demonstrating an approximate ratio of 2.0. Our research suggests that this scaling relationship should hold true for all symmetric nuclei, furthermore, we offer a possible explanation for this phenomenon.

    Comments:
    8 pages, 5 figures, 1 table, accepted by PLB
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2309.05909 [pdf]
    PLB(2024)·7 citations
  3. 03

    [Submitted on 12 Sept 2023]

    Extracting Kinetic Freeze-out Properties in High Energy Collisions Using a Multi-source Thermal Model

    Jia-Yu Chen🇨🇳 · Mai-Ying Duan🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿

    We study the transverse momentum () spectra of neutral pions and identified charged hadrons produced in proton--proton (), deuteron--gold (--Au), and gold--gold (Au--Au) collisions at the center of mass energy GeV. The study is made in the framework of a multi-source thermal model used in the partonic level. It is assumed that the contribution to the -value of any hadron comes from two or three partons with an isotropic distribution of the azimuthal angle. The contribution of each parton to the -value of a given hadron is assumed to obey any one of the standard (Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein) distributions with the kinetic freeze-out temperature and average transverse flow velocity. The -spectra of the final-state hadrons can be fitted by the superposition of two or three components. The results obtained from our Monte Carlo method are used to fit the experimental results of the PHENIX and STAR Collaborations. The results of present work serve as a suitable reference baseline for other experiments and simulation studies.

    Comments:
    18 pages, 8 figures. Advances in High Energy Physics, accepted
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2309.05923 [pdf]
    Adv.High Energy Phys.(2024)·3 citations
  4. 04

    [Submitted on 12 Sept 2023]

    Nuclear ground-state properties probed by the relativistic Hartree-Bogoliubov approach

    Zi Xin Liu · Yi Hua Lam · Ning Lu · Peter Ring

    Using the relativistic Hartree-Bogoliubov framework with separable pairing force coupled with the latest covariant density functionals, i.e., PC-L3R, PC-X, DD-PCX, and DD-MEX, we systematically explore the ground-state properties of all isotopes of Z=8-110. These properties consist of the binding energies, one- and two-neutron separation energies ( and ), root-mean-square radius of matter, of neutron, of proton, and of charge distributions, Fermi surfaces, ground-state spins and parities. We then predict the edges of nuclear landscape and bound nuclei for the isotopic chains from oxygen (Z=8) to darmstadtium (Z=110) based on these latest covariant density functionals. The number of bound nuclei predicted by PC-L3R, PC-X, DD-PCX, and DD-MEX, are 9004, 9162, 6799, and 7112, respectively. The root-mean-square deviations of () yielded from PC-L3R, PCX, DD-PCX, and DD-MEX are 0.962 (1.300) MeV, 0.920 (1.483) MeV, 0.993 (1.753) MeV, and 1.010 (1.544) MeV, respectively. The root-mean-square deviations of charge radius distributions of comparing the available experimental values with the theoretical counterparts resulted from PC-L3R, PC-X, DD-PCX, and DD-MEX are 0.035 fm, 0.037 fm, 0.035 fm, and 0.034 fm, respectively. We notice pronounced differences between the empirical and theoretical root-mean-square radii of neutron at nuclei near the neutron drip line of the Mg, Ca, and Kr isotopic chains, suggesting the possible existence of the halo or giant halo phenomena.

    Comments:
    Finalized version, 472 pages (arXiv version), 11 main figures (75 subfigures, colorblind-friendly colors), 6 tables, accepted on 18 December 2023 and to appear at Atomic Data and Nuclear Data Tables, data availability: https://github.com/lamyihua/nuclear-ground-state-properties
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2309.06371 [pdf]
    Atom.Data Nucl.Data Tabl.(2024)·11 citations
  5. 05

    [Submitted on 12 Sept 2023]

    Early time dynamics far from equilibrium via holography

    Matthias Kaminski🇺🇸 · Casey Cartwright🇺🇸 · Marco Knipfer🇺🇸 · Michael F. Wondrak🇳🇱 · Björn Schenke🇺🇸 · Marcus Bleicher🇩🇪

    We investigate the early time dynamics of heavy ion collisions studying the time evolution of the energy-momentum tensor as well as energy-momentum correlations within a uniformly thermalizing holographic QGP. From these quantities, we suggest a far-from equilibrium definition of shear viscosity, which is a crucial property of QCD matter as it significantly determines the generation of elliptic flow already at early times. During an exemplary initial heating phase of the holographic QGP the shear viscosity of entropy density ratio decreases down to 60%, followed by an overshoot to 110% of the near-equilibrium value, . Implications for the QCD QGP are discussed. Subsequently, we consider a holographic QGP which is Bjorken-expanding. Its energy-momentum tensor components have a known hydrodynamic attractor to which all time evolutions collapse independent of the initial conditions. Based on this, we propose a definition for a far from equilibrium speed of sound, and analytically compute its hydrodynamic attractor. Subjecting this Bjorken-expanding plasma to an external magnetic field and an axial chemical potential, we study the chiral magnetic effect far from equilibrium.

    Comments:
    7 pages, 4 figures, proceedings of the 11th International Conference on Hard and Electromagnetic Probes of High Energy Nuclear Collisions (Hard Probes 2023)
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2309.06435 [pdf]
    PoS(2024)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE