Phenomenological Scaling Relations for SQM Stars with a Massive s-Quark in Gravitationally Strong Magnetic Fields under the Spherical Symmetry Approximation

TL;DR

This paper derives phenomenological scaling relations for the maximum mass of Strange Quark Matter stars under strong magnetic fields, considering both massless and massive strange quarks, and revisits the equation of state without approximations.

Contribution

It introduces a new scaling formula for SQM star maximum mass that accounts for magnetic fields and quark mass effects, extending previous models.

Findings

Maximum mass increases with large strange quark mass.

Scaling relations depend on magnetic field and quark mass.

Electron contribution to energy density is significant at large quark masses.

Abstract

Scaling relations with the bag constant parameter are investigated for Strange Quark Matter (SQM) stars in the presence of gravitationally strong magnetic fields minimally coupled with matter, considering both massless and massive strange quark scenarios. Assuming a simple model for such coupling under the approximation of spherical symmetry, a phenomenological scaling formula for the maximum mass of stars is derived as a function of the surface magnetic field and the strange quark mass. This formula is applicable for all formally admissible values of the free parameters, and strict scaling with the bag constant is retained only for a vanishing strange quark mass. As a byproduct of this study, the mathematical structure of the equation of state for the relativistic SQM model with a massive strange quark is revisited without approximations. It is observed that the contribution of the electron term to the energy density cannot be neglected in the theoretical limit of large strange quark masses. Consequently, the maximum mass of SQM stars increases with sufficiently large strange quark mass, contrasting with the behavior observed for low strange quark masses.