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Nuclear Theory·nucl-th

Thursday·February 23, 2023

12 papers—7 primary·5 cross-listed

All12Primary7Cross-lists5
  1. 01

    [Submitted on 21 Feb 2023]

    Anchor-based optimization of energy density functionals

    A. Taninah · A. V. Afanasjev

    A new anchor-based optimization method of defining the energy density functionals (EDFs) is proposed. In this approach, the optimization of the parameters of EDF is carried out for the selected set of spherical anchor nuclei the physical observables of which are modified by the correction function which takes into account the global performance of EDF. It is shown that the use of this approach leads to a substantial improvement in global description of binding energies for several classes of covariant EDFs. The computational cost of defining a new functional within this approach is drastically lower as compared with the one for the optimization which includes the global experimental data on spherical, transitional and deformed nuclei into the fitting protocol.

    Comments:
    6 pages, 1 figure and 1 Table, in press as Letter in Phys. Rev. C. Includes "Supplemental-material.pdf" as a separate file with this submission. This file provides technical and numerical details on the anchor-based optimization method
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2302.10979 [pdf]
    PRC(2023)·11 citations
  2. 02

    [Submitted on 21 Feb 2023]

    Probing the incompressibility of dense hadronic matter near QCD phase transition in relativistic heavy-ion collisions

    Zhi-Min Wu🇨🇳 · Gao-Chan Yong🇨🇳

    Based on the extended hadronic transport model of relativistic heavy-ion collisions, the incompressibility of dense hadronic matter created in relativistic Au+Au heavy-ion collisions at GeV is studied. By comparing experimental proton directed flow, productions of strange hadrons , as well as their ratio , proton high-order cumulants to the model calculations, a large incompressibility of dense hadronic matter is obtained from nucleon observabels while a rather small incompressibility is needed to fit the data of strange hadrons. This may indicate hadronic matter possesses different incompressibilities in different density regions, i.e., the incompressibility may become stiffer from saturation density to a certain baryon density and then turn to soft before reaching hadron-quark phase transition. The study also shows that the incompressibility significantly affects the critical baryon density of hadron-quark phase transition.

    Comments:
    5 pages, 4 figures, accepted by PRC, in production
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2302.11065 [pdf]
    PRC(2023)·10 citations
  3. 03

    [Submitted on 22 Feb 2023]

    Manifestation of pairing modes in nuclear collisions

    A. Makowski · M. C. Barton · P. Magierski · K. Sekizawa · G. Wlazłowski

    We discuss the possible manifestation of pairing dynamics in nuclear collisions beyond the standard quasi-static treatment of pairing correlations. These involve solitonic excitations induced by pairing phase difference of colliding nuclei and pairing dynamic enhancement in the di-nuclear system formed by merging nuclei.

    Comments:
    2 figures, 56th Zakopane Conference On Nuclear Physics
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2302.11193 [pdf]
    Acta Phys.Polon.Supp.(2023)·2 citations
  4. 04

    [Submitted on 22 Feb 2023]

    Hartree-Fock-Bogoliubov study of quantum shell effects on the path to fission in Hg, U and Fm

    Rémi Bernard🇦🇺 · Cédric Simenel🇦🇺 · Guillaume Blanchon🇫🇷

    Quantum shell effects stabilising fission fragments with various shapes have been invoked as a factor determining the distribution of nucleons between the fragments at scission. Shell effects also induce asymmetric shapes in the nucleus on its way to fission well before the final fragments are (pre)formed. These shell effects are studied in fission of Hg, U and Fm with constrained Hartree-Fock-Bogoliubov calculations using the D1S parametrisation of the Gogny interaction. Strutinsky shell energy correction and single-particle energy level density near the Fermi surface are computed. Several neutron and proton shell effects are identified as drivers towards asymmetric fission. Shell effects are also used to identify the preformation of the fragments in the later stage of fission.

    Comments:
    11 pages, 7 figures. References updated
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2302.11237 [pdf]
    EPJA(2023)·18 citations
  5. 05

    [Submitted on 22 Feb 2023]

    Signatures of deuteron synthesis on the modified combinants in nuclear collisions

    Rahul R. Nair🇵🇱 · Grzegorz Wilk🇵🇱 · Zbigniew Włodarczyk🇵🇱

    The mechanism of deuteron production in heavy-ion collisions is shown to have a significant impact on the shape of the modified combinants of their multiplicity distribution. In light of this observation, an experimental study is proposed to tackle the long-standing problem of nuclei synthesis in hadronic and nuclear collisions. The proposed approach has the potential to provide stringent constraints on the models of deuteron synthesis.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2302.11248 [pdf]
    0 citations
  6. 06

    [Submitted on 22 Feb 2023]

    Frequencies of - and -oscillation modes in cold and hot compact stars

    Vivek Baruah Thapa · Mikhail V. Beznogov · Adriana R. Raduta · Pratik Thakur

    A large collection of equations of state (EOSs) built within the covariant density functional (CDF) theory of hadronic matter and allowing for density dependent (DD) couplings is employed to study polar - and - oscillations of cold and hot compact stars. Correlations between oscillation frequencies of cold purely nucleonic neutron stars (NSs), their global parameters as well as properties of nuclear matter (NM) are investigated by considering a set of models from Beznogov and Raduta, [Phys.~Rev.~C 107, 045803 (2023)], where a number of constraints on the saturation properties of NM, pure neutron matter (PNM) and the lower bound of the maximal NS mass were imposed within a Bayesian framework. The roles of finite temperature and exotic particle degrees of freedom, e.g., hyperons, -resonances, anti-kaon condensates or a hadron to quark phase transition, are addressed by employing a family of models publicly available on \textsc{CompOSE} and assuming idealized profiles of temperature or entropy per baryon and charge fraction. We find that finite temperature effects reduce the oscillation frequencies of nucleonic stars while the opposite effect is obtained for stars with exotic particle degrees of freedom. When the -law is employed to build finite temperature EOSs, errors in estimating oscillation modes frequencies are of the order of 10\% to 30\%, depending on the mass. Throughout this work the Cowling approximation is used.

    Comments:
    12 pages, 7 figures, 2 tables
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    2302.11469 [pdf]
    PRD(2023)·18 citations
  7. 07

    [Submitted on 22 Feb 2023]

    Recombination of mesons in ultra-relativistic heavy-ion collisions

    Biaogang Wu🇺🇸 · Zhanduo Tang🇺🇸 · Min He🇨🇳 · Ralf Rapp🇺🇸

    High-energy heavy-ion collisions have been suggested as a favorable environment for the production of mesons, due to a much larger abundance of charm and bottom quarks compared to elementary reactions. Motivated by recent CMS data for production in Pb-Pb(TeV) collisions at the LHC, we deploy a previously developed transport approach for charmonia and bottomonia to evaluate the kinetics of mesons throughout the fireball formed in these reactions. The main inputs to our approach are two transport parameters: the 's reaction rate and equilibrium limit. Both quantities are determined by previous calculations via a combination of charm and bottom sectors. In-medium binding energies of mesons are calculated from a thermodynamic -matrix with a lattice-QCD constrained potential, and figure in their inelastic reaction rates. Temperature-dependent equilibrium limits include charm- and bottom-quark fugacities based on their initial production. We compute the centrality dependence of inclusive production and transverse-momentum () spectra using two different recombination models, instantaneous coalescence and resonance recombination. The main uncertainty in the resulting nuclear modification factors, , is currently associated with the cross section in elementary collisions, caused by the uncertainty in the branching ratio for the decay. Our results indicate a large enhancement of the at low , with significant regeneration contributions up to GeV. Comparisons to CMS data are carried out but firm conclusions will require a more accurate value of the branching ratio, or alternative channels to measure the production in collisions.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2302.11511 [pdf]
    PRC(2024)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE