The symmetry energy ${\hat{I}}^3$ parameter of relativistic mean-field models

Abstract

The relativistic mean-field models tested in previous works against nuclear matter experimental values, critical parameters and macroscopic stellar properties are revisited and used in the evaluation of the symmetry energy ${\hat{I}}^3$ parameter obtained in three different ways. We have checked that independent of the choice made to calculate the ${\hat{I}}^3$ values, a trend of linear correlation is observed between ${\hat{I}}^3$ and the symmetry energy (${\mathcal{S}}_0$) and a more clear linear relationship is established between ${\hat{I}}^3$ and the slope of the symmetry energy ($L_0$). These results directly contribute to the arising of other linear correlations between ${\hat{I}}^3$ and the neutron star radii of $R_{1.0}$ and $R_{1.4}$, in agreement with recent findings. Finally, we have found that short-range correlations induce two specific parametrizations, namely, IU-FSU and DD-ME$\hat{I}´$, simultaneouslycompatible with the neutron star mass constraint of $1.93<M_{max}/M_{\odot }<2.05$ and with the overlap band for the $L_0\times {\mathcal{S}}_0$ region, to present ${\hat{I}}^3$ in the range of ${\hat{I}}^3=0.25\pm 0.05$.

11 pages, 6 figures. Version accepted for publication in Chinese Physics C