Thermodynamic consistency, quark mass scaling, and properties of strange matter

TL;DR

This paper develops a thermodynamically consistent model for strange quark matter with a new quark mass scaling, leading to stiffer equations of state and higher maximum masses for strange stars.

Contribution

It introduces a fully self-consistent thermodynamic framework and a new quark mass scaling that includes confinement and perturbative effects.

Findings

Equation of state becomes stiffer with the new model.

Maximum mass of strange stars can reach about 2 solar masses.

Thermodynamic consistency improves the reliability of strange matter predictions.

Abstract

The previous thermodynamic treatment for models with density and/or temperature dependent quark masses is shown to be inconsistent with the requirement of fundamental thermodynamics. We therefore study a fully self-consistent one according to the fundamental differential equation of thermodynamics. After obtaining a new quark mass scaling with the inclusion of both confinement and leading-order perturbative interactions, we investigate properties of strange quark matter in the fully consistent thermodynamic treatment. It is found that the equation of state become stiffer, and accordingly, the maximum mass of strange stars is as large as about 2 times the solar mass, if strange quark matter is absolutely or metastable.