Compact stars in a SU(3) Quark-Meson Model

TL;DR

This paper investigates whether a SU(3) quark-meson model can produce stable, massive quark stars consistent with recent pulsar observations, focusing on the model's parameters and their effects on the star's maximum mass.

Contribution

It introduces a SU(3) chiral quark-meson model with specific terms and parameters to analyze the feasibility of massive quark stars within this framework.

Findings

Large vector meson coupling and small vacuum pressure enable stars with over two solar masses.

Pure strange quark stars are only possible within a narrow parameter range.

The model constrains the conditions under which stable, massive quark stars can exist.

Abstract

The recent observations of the massive pulsars PSR J1614-2230 and of PSR J0348+0432 with about two solar masses implies strong constraints on the properties of dense matter in the core of compact stars. Effective models of QCD aiming to describe neutron star matter can thereby be considerably constrained. In this context, a chiral quark-meson model based on a SU(3) linear $\sigma$-model with a vacuum pressure and vector meson exchange is discussed in this work. The impact of its various terms and parameters on the equation of state and the maximum mass of compact stars are delineated to check whether pure quark stars with two solar masses are feasible within this approach. Large vector meson coupling constant and a small vacuum pressure allow for maximum masses of two or more solar masses. However, pure quark stars made of absolutely stable strange quark matter, so called strange stars, turn out to be restricted to a quite small parameter range.