Hyperon star in a modified quark meson coupling model

TL;DR

This paper models hyperon-rich neutron stars using a modified quark meson coupling approach, analyzing the equation of state and mass-radius relations to meet observational constraints.

Contribution

It introduces a self-consistent method to incorporate hyperons in the MQMC model and examines the impact of nonlinear meson interactions on neutron star properties.

Findings

Hyperons are included consistently in the EOS.

The maximum neutron star mass constraint of 2 solar masses is satisfied.

Nonlinear $ ho$-$ ho$ interactions do not significantly affect star mass predictions.

Abstract

We determine the equation of state (EOS) of nuclear matter with the inclusion of hyperons in a self-consistent manner by using a Modified Quark Meson Coupling Model (MQMC) where the confining interaction for quarks inside a baryon is represented by a phenomenological average potential in an equally mixed scalar-vector harmonic form. The hadron-hadron interaction in nuclear matter is then realized by introducing additional quark couplings to $\sigma$, $\omega$, and $\rho$ mesons through mean-field approximations. The effect of a nonlinear $\omega$-$\rho$ term on the equation of state is studied. The hyperon couplings are fixed from the optical potential values and the mass-radius curve is determined satisfying the maximum mass constraint of $2$~M$_{\odot}$ for neutron stars, as determined in recent measurements of the pulsar PSR J0348+0432. We also observe that there is no significant advantage of introducing the nonlinear $\omega$-$\rho$ term in the context of obtaining the star mass constraint in the present set of parametrizations.