Magnetized strange quark matter in a quasiparticle description

TL;DR

This paper extends a quasiparticle model to study magnetized strange quark matter, revealing how magnetic fields and QCD parameters influence its stability, equation of state, and potential maximum star mass.

Contribution

It introduces a self-consistent thermodynamic framework for magnetized strange quark matter with a density and magnetic field-dependent bag parameter.

Findings

Magnetic fields below 10^7 Gauss stabilize strange quark matter energetically.

The effective bag function exhibits a maximum at certain densities, not monotonic.

Magnetic field and QCD scale affect the equation of state and maximum star mass.

Abstract

The quasiparticle model is extended to investigate the properties of strange quark matter in a strong magnetic field at finite densities. For the density-dependent quark mass, self-consistent thermodynamic treatment is obtained with an additional effective bag parameter, which depends not only on the density but also on the magnetic field strength. The magnetic field makes strange quark matter more stable energetically when the magnetic field strength is less than a critical value of the order $10^7$ Gauss depending on the QCD scale $\Lambda$. Instead of being a monotonic function of the density for the QCD scale parameter $\Lambda>126$ MeV, the effective bag function has a maximum near $0.3\sim 0.4$ fm$^{-3}$. The influence of the magnetic field and the QCD scale parameter on the stiffness of the equation of state of the magnetized strange quark matter and the possible maximum mass of strange stars are discussed