Determining the density content of symmetry energy and neutron skin: an empirical approach

TL;DR

This paper presents an empirical method to constrain the symmetry energy slope parameter and neutron skin thickness in nuclei using precise empirical data and microscopic calculations, resulting in tighter bounds on these nuclear properties.

Contribution

It introduces a novel empirical approach combining empirical coefficients and microscopic models to better constrain symmetry energy parameters and neutron skin thickness.

Findings

Symmetry energy slope parameter L = 64 ± 5 MeV.

Neutron skin thickness of 208Pb = 0.188 ± 0.014 fm.

Method allows prediction of neutron skins for other nuclei.

Abstract

The density dependence of nuclear symmetry energy remains poorly constrained. Starting from precise empirical values of the nuclear volume and surface symmetry energy coefficients and the nuclear saturation density, we show how in the ambit of microscopic calculations with different energy density functionals, the value of the symmetry energy slope parameter $L$ alongwith that for neutron skin can be put in tighter bounds. The value of $L$ is found to be $L$= 64$\pm $5 MeV. For $^{208}$Pb, the neutron skin thickness comes out to be 0.188 $\pm $0.014 fm. Knowing $L$, the method can be applied to predict neutron skins of other nuclei.