Density dependence of symmetry energy and neutron skin thickness revisited using relativistic mean field models with nonlinear couplings

TL;DR

This study examines how the neutron skin thickness of nuclei relates to the symmetry energy slope parameter across different densities using relativistic mean field models with nonlinear meson couplings, highlighting model-dependent sensitivities.

Contribution

It systematically analyzes the density dependence of the neutron skin-symmetry energy relation within relativistic mean field models, emphasizing the importance of model-specific behavior at various densities.

Findings

Models with larger skin probe the slope parameter at suprasaturation densities.

Models with smaller skin are sensitive only at specific subsaturation densities.

Extrapolations to high densities from models fitted at lower densities should be approached cautiously.

Abstract

The correlation between neutron skin-thickness of a neutron-rich nucleus and slope parameter of symmetry energy is assessed as a function of density using relativistic mean field models containing non-linear couplings among different mesons. Models with larger skin were found to probe the slope parameter even at suprasaturation densities, whereas models with smaller skin were observed to be sensitive only at specific subsaturation density, connected to the average density of nuclei. Possible reasons behind this density dependence are explored systematically. These results might be model specific, which need to be reassessed in other type of interactions existing in the literature. Nevertheless, extrapolating the predictions at high densities from models, which are optimized by data at saturation or subsaturation densities, needs to be handled with care.