Nuclear Theory·nucl-th

Friday·May 23, 2025

8 papers—4 primary·4 cross-listed

01
Initial-State Charge Density Predicts Final-State Net Charge Flow in Heavy-Ion Collisions
Jefferson Sousa🇧🇷 · Matthew D. Sievert🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Patrick Carzon🇮🇩 · Matthew Luzum🇧🇷
We propose a new class of charge-conjugation-odd flow observables and use them to investigate the dynamics of conserved currents in simulations of relativistic heavy-ion collisions. Inspired by the success of the initial energy and momentum distributions at predicting final-state anisotropic flow, we construct systematically-improvable initial-state estimators for final net-charge flow observables, which we validate with numerical simulations. This opens the possibility of a multitude of new charge-dependent probes of heavy-ion collisions of different systems and energies.
nucl-thhep-phPLB(2026)·1 citation
02
$α +^{2} n +^{2} n$ 3-body cluster structures and dineutron breaking in $^{8} He$
Kosei Nakagawa · Yoshiko Kanada-En'yo
The $0_{2}^{+}$ state of $^{8} He$ has been discovered by a recent experiment, which suggested a developed cluster structure of spatially correlated neutron pairs, called "dineutrons" ( $^{2} n$ ). We aim to investigate the structure of $^{8} He (0_{1}^{+})$ and $^{8} He (0_{2}^{+})$ to clarify the monopole excitation mode in $^{8} He$ system while focusing on the $α +^{2} n +^{2} n$ cluster structures and the breaking of $^{2} n$ clusters. We apply a microscopic cluster model with the generator coordinate method for the $α +^{2} n +^{2} n$ cluster and $^{6} He +^{2} n$ cluster dynamics. The $p_{3/2}$ -closure component, which is induced by the spin-orbit force, is also incorporated. The present calculation reasonably reproduces the experimental data of the properties of $^{8} He$ , such as $2 n$ and $4 n$ separation energies, energy spectra, and radii. The spatially developed cluster structure of the $0_{2}^{+}$ state is obtained. The $0_{1}^{+}$ and $0_{2}^{+}$ states have dominant components of $α +^{2} n +^{2} n$ 3-body cluster, but contain significant $^{2} n$ breaking components which contribute to the energy gain and size shrinking of the $^{8} He$ system. The monopole excitation in $^{8} He$ is regarded as a radial excitation, which is similar to that in $^{12} C$ . The $α +^{2} n +^{2} n$ cluster structures play a dominant role in $^{8} He (0_{1, 2}^{+})$ , and the mixing of the dineutron breaking contributes to significant structural effects.
nucl-thPRC(2025)·3 citations
03
Seniority-two valence-shell building blocks of the octupole phonon
M. Scheck · R. Chapman · K. Mashtakov · R. Meeten · P.L. Sassarini · P. Spagnoletti
The relative ordering of $J^{-}$ levels of multiplets resulting from two-body excitations, which include a $J^{π} = 3^{-}$ state that can contribute to the octupole phonon, are investigated in a simplistic shell-model approach. To calculate the relative level ordering, harmonic oscillator wavefunctions and a residual $δ$ interaction are used. The simplistic approach confirms for the particle-particle channel, the often stated preference of the $Δ j = 3, Δ l = 3$ subshell combination over the $Δ j = 3, Δ l = 1$ subshell combination through an enhanced energy gain. Furthermore, it is shown that, in the particle-hole channel, the gain is less pronounced for the $Δ j = 3, Δ l = 3$ subshell configuration. In combination with the overall structure of an oscillator shell, these results explain the comparatively low excitation energy for 3 $_{1}^{-}$ excitations observed for the octupole-soft proton and neutron numbers predicted by various models.
nucl-thnucl-ex0 citations
04
Properties of the neutron star crust informed by nuclear structure data
Pietro Klausner🇫🇷 · Marco Antonelli🇫🇷 · Francesca Gulminelli🇫🇷
We perform a Bayesian analysis of the neutron star (NS) equation of state (EoS) based on a wide set of Skyrme functionals, derived from previous nuclear physics inferences. The novelty of this approach lies in starting from the full multidimensional posterior distribution of nuclear matter parameters, consistent with a comprehensive set of static and dynamic nuclear structure observables. We construct unified EoSs for $n p e μ$ matter, where the inner crust of the NS is treated using an extended Thomas-Fermi method, providing for the first time a fully consistent Bayesian treatment of the correlation of bulk with surface as well as with spin-orbit and effective mass parameters. We then employ a standard Bayesian framework to identify those EoSs that satisfy astrophysical constraints from NS mass measurements, the tidal deformability from GW170817, and NICER mass-radius observations. We also examine NS observables, such as the crustal moment of inertia, which is crucial in understanding pulsar glitches. Compared to previous works, we observe an increase in both the NS surface thickness and the crustal moment of inertia.
nucl-thastro-ph.HEPRC(2026)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE

Initial-State Charge Density Predicts Final-State Net Charge Flow in Heavy-Ion Collisions

α+2n+2n 3-body cluster structures and dineutron breaking in 8He

Seniority-two valence-shell building blocks of the octupole phonon

Properties of the neutron star crust informed by nuclear structure data

Affiliations

$α +^{2} n +^{2} n$ 3-body cluster structures and dineutron breaking in $^{8} He$