The induced surface tension contribution for the equation of state of neutron stars

TL;DR

This paper introduces a new equation of state for neutron stars that incorporates surface tension effects from interparticle interactions, aligning nuclear physics models with astrophysical observations.

Contribution

It presents a novel EoS including surface tension from interparticle interactions, consistent with nuclear matter properties and neutron star observations.

Findings

EoS matches nuclear matter properties and experimental constraints

Mass-radius relations align with astrophysical data

Optimal parameters for nuclear symmetry energy are identified

Abstract

We apply a novel equation of state (EoS) that includes the surface tension contribution induced by interparticle interaction and asymmetry between neutrons and protons, to the study of neutron star (NS) properties. This elaborated EoS is obtained from the virial expansion applied to multicomponent particle mixtures with hard core repulsion. The considered model is in full concordance with all the known properties of normal nuclear matter, provides a high-quality description of the proton flow constraints, hadron multiplicities created during the nuclear-nuclear collision experiments, and equally is consistent with astrophysical data coming from NS observations. The analysis suggests that the best model parameterization gives the incompressibility factor $K_{0}$, symmetry energy $J$, and symmetry energy slope $L$ at normal nuclear density equal to $200$ MeV, $30$ MeV, and $113.28-114.91$ MeV, respectively. The mass-radius relations found for NSs computed with this EoS are consistent with astrophysical observations.