Asymmetric nuclear matter and neutron-skin in extended relativistic mean field model

TL;DR

This paper investigates the density dependence of symmetry energy in asymmetric nuclear matter using an extended relativistic mean field model with various parameterizations, analyzing implications for neutron-skin thickness and model consistency.

Contribution

It introduces and analyzes 26 parameterizations of the ERMF model including mixed interactions, aligning symmetry energy behavior with empirical constraints and neutron-skin data.

Findings

Symmetry energy behavior consistent with empirical data.

Neutron-skin thickness in $^{208}$Pb predicted as 0.20-0.24 fm.

Mixed interaction terms significantly influence symmetry energy density dependence.

Abstract

The density dependence of the symmetry energy, instrumental in understanding the behaviour of the asymmetric nuclear matter, is investigated within the extended relativistic mean field (ERMF) model which includes the contributions from the self and mixed interaction terms for the scalar-isoscalar ($\sigma$), vector-isoscalar ($\omega$) and vector-isovector ($\rho$) mesons upto the quartic order. Each of the 26 different parameterizations of the ERMF model employed are compatible with the bulk properties of the finite nuclei. The behaviour of the symmetry energy for several parameter sets are found to be consistent with the empirical constraints on them as extracted from the analyses of the isospin diffusion data. The neutron-skin thickness in the $^{208}$Pb nucleus for these parameter sets of the ERMF model lie in the range of $\sim 0.20 - 0.24$ fm which is in harmony with the ones predicted by the Skyrme Hartree-Fock model. We also investigate the role of various mixed interaction terms which are crucial for the density dependence of the symmetry energy.