Strange quark matter and proto-strange stars in an equivaparticle model

TL;DR

This paper investigates the properties of strange quark matter and proto-strange stars using an equivparticle model with new quark mass scaling, revealing the impact of perturbative interactions and conditions for massive proto-strange stars.

Contribution

It introduces a novel quark mass scaling and thermodynamic treatment within the equivparticle model, enhancing understanding of strange star properties and maximum mass.

Findings

Perturbative interaction significantly affects strange quark matter properties.

Energy per baryon increases with temperature, free energy decreases and becomes negative.

Maximum mass of proto-strange stars exceeds twice the solar mass at T=50 MeV.

Abstract

The properties of strange quark matter and the structures of (proto-)strange stars are studied within the framework of an equivparticle model, where a new quark mass scaling and self-consistent thermodynamic treatment are adopted. Our results show that the perturbative interaction has a strong impact on the properties of strange quark matter. It is found that the energy per baryon increases with temperature, while the free energy decreases and eventually becomes negative. At fixed temperatures, the pressure at the minimum free energy per baryon is zero, suggesting that the thermodynamic self-consistency is preserved. Additionally, the sound velocity v in quark matter approaches to the extreme relativistic limit (c/sqrt(3)) as the density increases. By increasing the strengths of confinement parameter D and perturbation parameter C, the tendency for v to approach the extreme relativistic limit at high density is slightly weakened. For (proto-)strange stars, in contrast to the quark mass scalings adopted in previous publications, the new quark mass scaling can accommodate massive proto-strange stars with their maximum mass surpassing twice the solar mass at T = 50 MeV.