Inverse magnetic catalysis in the Polyakov-Nambu-Jona-Lasinio and entangled Polyakov-Nambu-Jona-Lasinio models

TL;DR

This paper explores how external magnetic fields influence the QCD phase diagram at finite temperature using Polyakov-Nambu-Jona-Lasinio models, successfully reproducing lattice QCD results and demonstrating inverse magnetic catalysis effects.

Contribution

It introduces magnetic field-dependent scalar couplings in PNJL models to qualitatively match lattice QCD findings on quark condensates and Polyakov loop behavior under magnetic fields.

Findings

Quark condensates are enhanced at low and high temperatures but suppressed near transition temperatures under magnetic fields.

Polyakov loop increases with magnetic field strength.

Models reproduce qualitative lattice QCD results for magnetic field effects.

Abstract

We investigate the QCD phase diagram at zero chemical potential and finite temperature in the presence of an external magnetic field within the three flavor Polyakov-Nambu-Jona-Lasinio and entangled Polyakov-Nambu-Jona-Lasinio models looking for the inverse magnetic catalysis. Two scenarios for a scalar coupling parameter dependent on the magnetic field intensity are considered. These dependencies of the coupling allow to reproduce qualitatively lattice QCD results for the quark condensates and for the Polyakov loop: due to the magnetic field the quark condensates are enhanced at low and high temperatures and suppressed for temperatures close to the transition temperatures while the Polyakov loop increases with the increasing of the magnetic field.