Meson properties in magnetized quark matter

TL;DR

This paper investigates how magnetic fields influence meson properties in quark matter using a Nambu--Jona-Lasinio model, revealing changes in meson masses and quark interaction regions due to magnetic effects.

Contribution

It introduces a method to derive effective meson Lagrangian with magnetic coupling, analyzing meson masses and interactions in magnetic fields within the NJL framework.

Findings

Magnetic field alters meson masses and screening lengths.

Quark interaction regions deform from spherical to ellipsoidal under magnetic influence.

Neutral pion remains the Goldstone mode affecting thermodynamics.

Abstract

We study neutral and charged meson properties in magnetic field. Taking bosolization method in a two-flavor Nambu--Jona-Lasinio model, we derive effective meson Lagrangian density with minimal coupling to the magnetic field, by employing derivative expansion for both the meson fields and Schwinger phases. We extract from the effective Lagrangian density the meson curvature, pole and screening masses. As the only Goldstone mode, the neutral pion controls the thermodynamics of the system and propagates the lang range quark interaction. The magnetic field breaks down the space symmetry, and the quark interaction region changes from a sphere in vacuum to a ellipsoid in magnetic field.