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Nuclear Theory·nucl-th

Thursday·June 29, 2023

9 papers—4 primary·5 cross-listed

All9Primary4Cross-lists5
  1. 01

    A method for probing the formation of quark matter

    Gao-Chan Yong🇨🇳

    Based on a multi-phase transport model for relativistic heavy-ion collisions, effects of the parton scatterings on the production of strangeness in relativistic heavy-ion collisions are studied. It is found that the distributions of strange quark and strange baryon, especially for the double strangeness , are significantly affected by the parton scatterings in heavy-ion collisions below 10 GeV. Given parton scatterings as a signal of the formation of quark matter, the transverse momentum distribution of the ratio of single and double strangeness produced in heavy-ion collisions may serve as a potential probe of the emergence of quark matter, or equivalently, the occurrence of hadron-quark phase transition in relativistic heavy-ion collisions.

    nucl-thnucl-exPLB(2023)·6 citations
  2. 02

    Phase diagram determination at fivefold nuclear compression

    Gao-Chan Yong🇨🇳

    In the standard model of particle physics, the strong force is characterized by the theory of quantum chromodynamics (QCD). It is commonly understood from QCD properties that hadrons, at sufficiently high temperatures or densities, melt into their constituent quarks, thereby undergoing a deconfinement transition to a new phase of quarks and gluons, often referred to as quark matter or quark-gluon plasma (QGP) \cite{qcd00,qcd01}. Although QGP has been observed in relativistic heavy-ion collisions \cite{qgp1,qgp2}, uncertainties remain about when the onset of deconfinement occurs. After comparing simulations from a reliable hadron and quark relativistic transport model with recent data from the STAR experiment, we determined that the onset of the hadron-quark phase transition occurs at about five times nuclear compression, corresponding to temperature 112 MeV and baryon chemical potential 586 MeV, in the nuclear matter phase diagram. This discovery has significant implications for the studies of both the early and present universe \cite{ann2006}, including the fraction of dark matter formed in the early universe \cite{bhd2016,bhf1997,pbh20} and the structure and dynamics of neutron stars and their mergers \cite{nature2020}.

    nucl-thnucl-exPLB(2024)·10 citations
  3. 03

    Missed prediction of the neutron halo in Mg

    K. Y. Zhang · S. Q. Yang · J. L. An · S. S. Zhang · P. Papakonstantinou · M.-H. Mun · Y. Kim · H. Yan

    Halo phenomena have long been an important frontier in both experimental and theoretical nuclear physics. Mg was identified as a halo nucleus in 2014 and remains the heaviest nuclear halo system to date. While the halo phenomenon in Mg was not predicted before the discovery, its description has been still challenging afterwards. In this Letter, we report a microscopic and self-consistent description of the neutron halo in Mg using the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) that was developed in 2010. The experimental neutron separation energies and empirical matter radii of neutron-rich magnesium isotopes as well as the deformed -wave halo characteristics of Mg are well reproduced without any free parameters. In particular, the orbital occupied by the halo neutron in Mg, exhibiting -wave components comparable to those suggested in experiments, remains consistent across various employed density functionals including PC-F1, PC-PK1, NL3*, and PK1. The DRHBc theory investigated only even-even magnesium isotopes in previous works and for that reason missed predicting Mg as a halo nucleus before 2014. Although the core and the halo of Mg are both prolate, higher-order shape decoupling on the hexadecapole and hexacontatetrapole levels is predicted.

    nucl-thPLB(2023)·48 citations
  4. 04

    Neutrino spectrum and energy loss rates due to weak processes on hot Fe in pre-supernova environment

    Alan A. Dzhioev · A. V. Yudin · N. V. Dunina-Barkovskaya · A. I. Vdovin

    Applying TQRPA calculations of Gamow--Teller strength functions in hot nuclei, we compute the (anti)neutrino spectra and energy loss rates arising from weak processes on hot Fe under pre-supernova conditions. We use a realistic pre-supernova model calculated by the stellar evolution code MESA. Taking into account both charged and neutral current processes, we demonstrate that weak reactions with hot nuclei can produce high-energy (anti)neutrinos. We also show that, for hot nuclei, the energy loss via (anti)neutrino emission is significantly larger than that for nuclei in their ground state. It is found that the neutral current de-excitation via the -pair emission is presumably a dominant source of antineutrinos. In accordance with other studies, we confirm that the so-called single-state approximation for neutrino spectra might fail under certain pre-supernova conditions. }

    nucl-thastro-ph.SRParticles(2023)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE