Driving chiral phase transition with ring diagram

TL;DR

This paper investigates how ring diagram corrections to four-quark interactions influence chiral phase transitions and inverse magnetic catalysis in an effective quark model, highlighting the roles of confinement and the Polyakov loop.

Contribution

It introduces a method to incorporate ring diagram effects into the quark gap equation, revealing their impact on transition temperatures and magnetic catalysis phenomena.

Findings

Ring diagram dressing lowers the chiral transition temperature.

The model reproduces inverse magnetic catalysis at finite temperatures.

Confining forces via the Polyakov loop reinforce inverse magnetic catalysis.

Abstract

We study the dressing of four-quark interaction by the ring diagram, and its feeding back to the quark gap equation, in an effective chiral quark model. Implementing such an in-medium coupling naturally reduces the chiral transition temperature in a class of chiral models, and is capable of generating the inverse magnetic catalysis at finite temperatures. We also demonstrate the important role of confining forces, via the Polyakov loop, in a positive feedback mechanism which reinforces the inverse magnetic catalysis.