Optimization of relativistic mean field model for finite nuclei to neutron star matter

TL;DR

This paper optimizes relativistic mean-field model parameters to accurately describe finite nuclei and neutron star matter, introducing two new parameter sets that improve predictions of binding energies and equations of state.

Contribution

The paper introduces two new RMF parameter sets, BSP and IUFSU*, with a focus on high-density behavior and the role of meson cross-couplings, enhancing nuclear matter modeling.

Findings

New parameter sets improve binding energy predictions.

Enhanced modeling of neutron matter equations of state.

Highlighting the significance of omega-sigma cross coupling.

Abstract

We have optimized the parameters of extended relativistic mean-field model using a selected set of global observables which includes binding energies and charge radii for nuclei along several isotopic and isotonic chains and the iso-scalar giant monopole resonance energies for the $^{90}$Zr and $^{208}$Pb nuclei. The model parameters are further constrained by the available informations on the energy per neutron for the dilute neutron matter and bounds on the equations of state of the symmetric and asymmetric nuclear matter at supra-nuclear densities. Two new parameter sets BSP and IUFSU* are obtained, later one being the variant of recently proposed IUFSU parameter set. The BSP parametrization uses the contributions from the quartic order cross-coupling between $\omega$ and $\sigma$ mesons to model the high density behaviour of the equation of state instead of the $\omega$ meson self-coupling as in the case of IUFSU* or IUFSU. Our parameter sets yield appreciable improvements in the binding energy systematics and the equation of state for the dilute neutron matter. The importance of the quartic order $\omega-\sigma$ cross coupling term of the extended RMF model, as often ignored, is realized.