Non-equilibrium study of the Chiral Magnetic Effect from real-time simulations with dynamical fermions

TL;DR

This paper develops a real-time lattice simulation method with dynamical fermions to study non-equilibrium chiral phenomena like the CME and CSE in gauge theories, providing first-principles insights into their dynamics.

Contribution

It introduces a novel real-time lattice approach with dynamical fermions and operator definitions for Wilson and overlap fermions to study anomalous transport phenomena.

Findings

Demonstrates real-time dynamics of fermions during sphaleron transitions

Analyzes fermion mass and magnetic field effects on CME and CSE signatures

Highlights important factors for macroscopic modeling of anomalous transport

Abstract

We present a real-time lattice approach to study the non-equilibrium dynamics of vector and axial charges in $SU(N) \times U(1)$ gauge theories. Based on a classical description of the non-Abelian and Abelian gauge fields, we include dynamical fermions and develop operator definitions for (improved) Wilson and overlap fermions that allow us to study real-time manifestations of the axial anomaly from first principles. We present a first application of this approach to anomalous transport phenomena such as the Chiral Magnetic Effect (CME) and Chiral Separation Effect (CSE) by studying the dynamics of fermions during and after a $SU(N)$ sphaleron transition in the presence of a $U(1)$ magnetic field. We investigate the fermion mass and magnetic field dependence of the suggested signatures of the CME and CSE and point out some important aspects which need to be accounted for in the macroscopic description of anomalous transport phenomena.