Chiral Magnetic Effect and QCD Phase Transitions with Effective Models

TL;DR

This paper investigates how the chiral phase transition affects the chiral magnetic effect in QCD, showing that key observables are suppressed at the critical temperature, which can help identify phase transitions in experiments.

Contribution

It introduces a model-based analysis of the impact of QCD phase transitions on the chiral magnetic effect and proposes experimental observables for detecting these transitions.

Findings

Chiral electric current density drops sharply at the critical temperature.

Electric charge differences are suppressed during the phase transition.

Azimuthal charged-particle correlations can signal QCD phase transitions.

Abstract

We study the influence of the chiral phase transition on the chiral magnetic effect. The chiral electric current density along the magnetic field, the electric charge difference between on each side of the reaction plane, and the azimuthal charged-particle correlations as functions of the temperature during the QCD phase transitions are calculated. It is found that with the decrease of the temperature, the chiral electric current density, the electric charge difference, and the azimuthal charged-particle correlations all get a sudden suppression at the critical temperature of the chiral phase transition, because the large quark constituent mass in the chiral symmetry broken phase quite suppresses the axial anomaly and the chiral magnetic effect. We suggest that the azimuthal charged-particle correlations (including the correlators divided by the total multiplicity of produced charged particles which are used in current experiments and another kind of correlators not divided by the total multiplicity) can be employed to identify the occurrence of the QCD phase transitions in RHIC energy scan experiments.