Strange matter and strange stars in a thermodynamically self-consistent perturbation model with running coupling and running strange quark mass

TL;DR

This paper develops a thermodynamically consistent perturbative QCD model with running coupling and strange quark mass to study strange quark matter and compact star properties, predicting stable strange matter and massive quark stars.

Contribution

It introduces a self-consistent thermodynamic framework with a new term acting as a chemical-potential dependent bag constant, enhancing previous models.

Findings

Strange quark matter can be absolutely stable.

Maximum quark star mass is about 2 solar masses.

Star radius can reach approximately 11 km.

Abstract

A quark model with running coupling and running strange quark mass, which is thermodynamically self-consistent at both high and lower densities, is presented and applied to study properties of strange quark matter and structure of compact stars. An additional term to the thermodynamic potential density is determined by meeting the fundamental differential equation of thermodynamics. It plays an important role in comparatively lower density and ignorable at extremely high density, acting as a chemical-potential dependent bag constant. In this thermodynamically enhanced perturbative QCD model, strange quark matter still has the possibility of being absolutely stable, while the pure quark star has a sharp surface with a maximum mass as large as about 2 times the solar mass and a maximum radius of about 11 kilometers.