Nuclear Theory·nucl-th

Tuesday·June 4, 2024

14 papers—4 primary·10 cross-listed

01
Methodology for Analyzing Proton Multiplicity Fluctuations with Azimuthal Partitions in Heavy-Ion Collisions
Dylan Neff🇺🇸 · Zhongling Ji🇺🇸 · Roli Esha🇺🇸 · Gang Wang🇺🇸 · Huan Huang🇺🇸
A primary objective in high-energy heavy-ion collisions is to investigate the phase transition between confined and deconfined color matter. Complementary to the cumulants of conserved charges integrated over the full azimuth, we introduce a novel experimental approach to explore particle fluctuations in azimuthal partitions, which are potentially sensitive to the first-order phase transition in heavy-ion collisions. We evaluate proton multiplicity ( $N_{w}$ ) fluctuations in azimuthal partitions of width $w$ to quantitatively estimate the clustering tendency among these protons. The $Δ σ^{2}$ observable is defined as the normalized difference between the variance of the $N_{w}$ distribution and the binomial baseline. We demonstrate the feasibility and characteristics of this observable through simulations using the AMPT and MUSIC+FIST models. We also use a Gaussian correlation model to illustrate that the dependence of $Δ σ^{2}$ on $w$ can be parameterized to accurately extract the strength and the range of the input interaction among protons.
nucl-thhep-phnucl-exPRC(2024)·1 citation
02
Finite-temperature equations of state of compact stars with hyperons: three-dimensional tables
Stefanos Tsiopelas🇵🇱 · Armen Sedrakian🇵🇱 · Micaela Oertel🇫🇷
We construct tables of finite temperature equation of state (EoS) of hypernuclear matter in the range of densities, temperatures, and electron fractions that are needed for numerical simulations of supernovas, proto-neutron stars, and binary neutron star mergers and cast them in the format of {\sc CompOSE} database. The tables are extracted from a model that is based on covariant density functional (CDF) theory that includes the full $J^{P} = 1/ 2^{+}$ baryon octet in a manner that is consistent with the current astrophysical and nuclear constraints. We employ a parameterization with three different values of the slope of the symmetry energy $L_{sym} = 30$ , 50 and 70 MeV and fixed skewness $Q_{sat} = 400$ MeV for above saturation matter. A model for the EoS of inhomogeneous matter is matched at sub-saturation density to the high-density hypernuclear EoS. We discuss the generic features of the resulting EoS and the composition of matter as a function of density, temperature, and electron fraction. The nuclear characteristics and strangeness fraction of these models are compared to the alternatives from the literature. The integral properties of static and rapidly rotating compact stars in the limit of zero temperature are discussed and confronted with the multimessenger astrophysical constraints.
nucl-thastro-ph.HEastro-ph.SREPJA(2024)·26 citations
03
Study of the alpha-particle monopole transition form factor
M. Viviani · A. Kievsky · L.E. Marcucci · L. Girlanda
The 4He monopole form factor is studied by computing the transition matrix element of the electromagnetic charge operator between the 4He ground-state and the p+3H and n+3He scattering states. The nuclear wave functions are calculated using the hyperspherical harmonic method, by starting from Hamiltonians including two- and three-body forces derived in chiral effective field theory. The electromagnetic charge operator retains, beyond the leading order (impulse approximation) term, also higher order contributions, as relativistic corrections and meson-exchange currents. The results for the monopole form factor are in fairly agreement with recent MAMI data. Comparison with other theoretical calculations are also provided.
nucl-thFew Body Syst.(2024)·6 citations
04
Reexamination of antinucleon-nucleon interactions in covariant chiral effective field theory
Yang Xiao🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳
Motivated by the recent progress in developing high-precision relativistic chiral nucleon-nucleon interactions, we study the antinucleon-nucleon interaction in a hybrid approach where the real part of the potential is constructed in the leading-order covariant chiral effective field theory, and the imaginary part is described following the procedure adopted in the heavy baryon chiral effective field theory. The phase shifts and inelasticities with $J \leq 1$ are obtained and compared to those calculated in the next-to-leading order heavy baryon chiral effective field theory. For most partial waves, the descriptions of phase shifts and inelasticities in the hybrid approach are comparable to those in the next-to-leading order heavy baryon chiral effective field theory, confirming the relatively faster convergence of the relativistic approach observed in the nucleon-nucleon sector. In addition, we search for bound states/resonances near the $N ˉ N$ threshold and find several structures that can be associated with those states recently observed by the BESIII Collaboration.
nucl-thhep-phPRC(2024)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE

Methodology for Analyzing Proton Multiplicity Fluctuations with Azimuthal Partitions in Heavy-Ion Collisions

Finite-temperature equations of state of compact stars with hyperons: three-dimensional tables

Study of the alpha-particle monopole transition form factor

Reexamination of antinucleon-nucleon interactions in covariant chiral effective field theory

Affiliations