Role of higher order couplings in the presence of kaons in relativistic mean field description of neutron stars

TL;DR

This paper investigates how higher order couplings and kaon condensation influence the equation of state and mass of neutron stars within relativistic mean field models, aligning theoretical predictions with observational data.

Contribution

It demonstrates the significant impact of higher order couplings and kaons on neutron star properties, using a model fitted to nuclear data and comparing multiple interaction parameter sets.

Findings

Higher order couplings reduce neutron star mass at high densities.

Kaons further decrease neutron star mass, matching observational constraints.

Neutron star composition varies with different interaction parameters.

Abstract

We discuss the role of higher order couplings in conjunction with kaon condensation using recent versions of relativistic mean field models.We focus on an interaction (G2) in which all the parameters are obtained by fitting the finite nuclear data and successfully applied to reproduce a variety of nuclear properties. Our results show that the higher order couplings play a significant role at higher densities where kaons dominate the behavior of the equation of state. We compare our results with other interactions (NLl, NL3, G1, and FSUGold) and show that the new couplings bring down the mass of a neutron star (NS), which is further reduced in the presence of kaons to yield results consistent with the present observational constraints. We show that the composition of the NS varies with the parameter sets.