Magnetized quark matter with a magnetic-field dependent coupling

TL;DR

This paper investigates how a magnetic-field dependent coupling affects the properties and stability of magnetized quark matter within the NJL model, revealing non-monotonous mass behavior and enhanced stability of strange quark matter.

Contribution

It introduces a magnetic-field dependent running coupling into the NJL model and analyzes its impact on quark matter properties and stability, a novel approach compared to constant coupling models.

Findings

Quark masses vary non-monotonously with magnetic field strength.

Magnetized quark matter with running coupling is more stable than with constant coupling.

Strange quark matter can be absolutely stable under strong magnetic fields.

Abstract

It was recently derived that the QCD running coupling is a function of the magnetic field strength under the strong magnetic field approximation. Inspired by this progress and based on the self-consistent solutions of gap equations, the properties of two-flavor and three-flavor quark matter are studied in the framework of the Nambu-Jona-Lasinio model with a magnetic-field dependent running coupling. We find that the dynamical quark masses as functions of the magnetic field strength are not monotonous in the fully chirally broken phase. Furthermore, the stability of magnetized quark matter with the running coupling is enhanced by lowering the free energy per baryon, which is expected to be more stable than that of the conventional constant coupling case. It is concluded that the magnetized strange quark matter described by running coupling can be absolutely stable.