Quark matter under strong magnetic fields in the Nambu--Jona-Lasinio Model

TL;DR

This study uses the Nambu--Jona-Lasinio model with a large-N_c approximation to analyze quark matter under strong magnetic fields, revealing effects on magnetar properties and the equation of state at extremely high magnetic intensities.

Contribution

It introduces a detailed analysis of quark matter in strong magnetic fields within the NJL model, highlighting the impact on magnetar characteristics and the equation of state.

Findings

Magnetar masses and radii increase with magnetic field strength.

Very large magnetic fields (≥10^{18} G) significantly affect the equation of state.

Landau level filling causes kinks in effective mass and related quantities.

Abstract

In the present work we use the large-$N_c$ approximation to investigate quark matter described by the SU(2) Nambu--Jona-Lasinio model subject to a strong magnetic field. The Landau levels are filled in such a way that usual kinks appear in the effective mass and other related quantities. $\beta$-equilibrium is also considered and the macroscopic properties of a magnetar described by this quark matter is obtained. Our study shows that the magnetar masses and radii are larger if the magnetic field increases but only very large fields ($\ge 10^{18}$ G) affect the EoS in a non negligible way.