Nuclear Theory·nucl-th

Monday·June 9, 2025

11 papers—5 primary·6 cross-listed

01
[Submitted on 5 Jun 2025]
Simulated-Annealing Optimization of Mean-Field Parameters in a Correlated-Basis Nuclear Model with Realistic Short-Range Correlations
Tianyang Ma · Shalom Shlomo
We optimize a six-parameter spherical Woods-Saxon mean field within a first-order correlated-basis-function description of finite nuclei containing central, spin-isospin, and tensor Short-Range Correlations (SRC). Monte Carlo importance sampling makes the multidimensional simulated-annealing search practical. The final objective contains 17 selected charge radii compared with a common theoretical scale of 0.030 fm. This light-to-heavy set is a representative compromise between mass-isospin coverage and the cost of repeatedly evaluating the correlated objective;Two independent fits are performed: S/S, in which the SRC theory uses its own fitted parameters, and 0/0, in which the no-SRC theory uses a separately fitted parameter set. A diagnostic S/0 calculation inserts the no-SRC-fitted parameters into the SRC theory. Its radius metric is 17.49 times the S/S value, demonstrating that the mean field must be refitted when explicit SRC are introduced. After separate optimization, radii, charge densities, and elastic form factors show no universal advantage for either consistent route. The corrected genuinely off-diagonal OBDM retains both uncorrelated kernels and the complete spectator-exchange spin contraction. In momentum space, the correlated S/S and diagnostic S/0 calculations generate the several-percent high-momentum strength observed in 12C and 40Ca, whereas the consistent no-SRC route 0/0 does not. The high-momentum tail is therefore the clearest signature of explicit SRC in the present calculation.
Comments:
Will be submitted to Nuclear Physics A
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.05512 [pdf]
0 citations
02
[Submitted on 5 Jun 2025]
Bayesian Inference of the Landau Parameter $G_{0}^{'}$ from Joint Gamow-Teller Measurements
Zidu Lin · Gianluca Colò · A. W. Steiner · Amber Stinson
The Landau-Migdal parameter $G_{0}^{'}$ characterizes the main part of the spin-isospin dependent nucleon-nucleon interaction. Consequently, the $G_{0}^{'}$ is closely related to the Gamow-Teller resonance (GTR), the beta and double-beta decay rates of finite nuclei, the response of hot and dense nucleonic matter that modifies the neutrino-nucleon absorption rates in core-collapse supernovae (CCSNe) and binary neutron star (BNS) mergers, and finally the critical density for pion condensation in neutron stars. In this letter, for the first time, we report the $G_{0}^{'}$ with quantified uncertainty in the framework of Bayesian inference, using a self-consistent standard Skyrme Random Phase Approximation (RPA) model and joint constraints from experimental GTR measurements on $^{208} Pb$ , $^{132} Sn$ , $^{90} Zr$ . Our extracted $G_{0}^{'}$ is $0.48 \pm 0.034$ , which is close to the prediction of a few existing Skyrme models that consider spin-isospin observables but smaller than the traditional ones extracted from pion-exchange models. We hint to possible reasons for this deviation, like the value of the nucleon effective mass $\frac{m ^{*}}{m}$ . The $G_{0}^{'}$ values extracted in this work may guide the construction of new energy density functionals that aims to self-consistently describe the dense matter properties in the spin-isospin channel.
Comments:
The scope of this manuscript is refined to focus on the Bayesian study of $G_{0}^{'}$ . The study of neutrino opacity and the correlation emerging from the Bayesian posterior of Skyrme models will be presented in a separate work (in preparation)
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2506.05564 [pdf]
3 citations
03
[Submitted on 5 Jun 2025]
Bayesian inference of neutron star crust properties using an ab initio-benchmarked meta-model
S. Burrello🇮🇹 · F. Gulminelli🇫🇷 · M. Antonelli🇫🇷 · M. Colonna🇮🇹 · A. Fantina🇫🇷
Accurate modeling of the neutron star crust is essential for interpreting multimessenger observations and constraining the nuclear equation of state (EoS). However, standard phenomenological EoS models often rely on heuristic extrapolations in the low-density regime, which are inconsistent with microscopic predictions. In this work, we refine a unified meta-modeling framework for the EoS by incorporating low-density corrections based on energy density functionals constrained by ab initio neutron-matter calculations. Using Bayesian inference to combine information from astrophysical observations, nuclear theory, and experiments, we assess the impact of these corrections on key crustal properties, including the crust-core transition density and pressure, crustal composition, and moment of inertia. The improved model reduces uncertainties in the inner crust and emphasizes the importance of low-density physics in EoS modeling, highlighting the value of integrating both theoretical and observational constraints across densities to robustly describe the EoS. Moreover, the adopted approach can be readily applied to any existing EoS model to provide a solid framework for interpreting upcoming high-precision multimessenger data.
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2506.05603 [pdf]
PRC(2025)·12 citations
04
[Submitted on 6 Jun 2025]
Femtoscopic signatures of unique nuclear structures in relativistic collisions
Daniel Kincses🇭🇺
One of the most vital topics of today's high-energy nuclear physics is the investigation of the nuclear structure of the collided nuclei. Recent studies at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) have shown that several observables, such as the collective flow and transverse-momentum correlations of the produced particles, can be sensitive to various nuclear structure and deformation parameters. Femtoscopy, another essential tool for investigating the space-time geometry of the matter created in nuclear collisions, has not yet been widely applied to such studies. Using a multiphase transport model (AMPT), in this Letter, it is demonstrated that the femtoscopic source parameters of pion pairs can also serve as a robust signal of unique nuclear structure. Through an analysis of $^{208}$ Pb+ $^{20}$ Ne and $^{208}$ Pb+ $^{16}$ O collisions at $s_{N N}$ = 68.5 GeV, two collision systems especially relevant to the SMOG2 program of the LHCb experiment, it is shown that a deformed initial shape can significantly affect femtoscopic source parameters. This study highlights the importance of expanding the nuclear structure investigations to femtoscopic observables and serves as a baseline for numerous possible future studies in this new direction.
Comments:
8 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2506.05849 [pdf]
PRResearch(2025)·7 citations
05
[Submitted on 6 Jun 2025]
Representing Equations of State With Strong First-Order Phase Transitions
Lee Lindblom · Steve M. Lewis · Fridolin Weber
Parametric representations of the high-density nuclear equation of state are used in constructing models for interpreting the astrophysical observations of neutron stars. This study explores how accurately equations of state with strong first-order phase transitions can be represented using spectral or piecewise analytic methods that assume no {\it{a priori}} knowledge of the location or the strength of the phase transition. The model equations of state used in this study have phase transitions strong enough to induce a gravitational instability that terminates the sequence of stable neutron stars. These equations of state also admit a second sequence of stable stars with core matter that has undergone this strong first-order phase transition (possibly driven by quark deconfinement). These results indicate that spectral representations generally achieve somewhat higher accuracy than piecewise analytic representations having the same number of parameters. Both types of representation show power-law convergence at approximately the same rate.
Comments:
9 pages, 15 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
arXiv:
2506.06201 [pdf]
PRD(2025)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Simulated-Annealing Optimization of Mean-Field Parameters in a Correlated-Basis Nuclear Model with Realistic Short-Range Correlations

Bayesian Inference of the Landau Parameter G0′​ from Joint Gamow-Teller Measurements

Bayesian inference of neutron star crust properties using an ab initio-benchmarked meta-model

Femtoscopic signatures of unique nuclear structures in relativistic collisions

Representing Equations of State With Strong First-Order Phase Transitions

Affiliations

Bayesian Inference of the Landau Parameter $G_{0}^{'}$ from Joint Gamow-Teller Measurements