Chiral magnetic effect in the presence of an external axial-vector field

TL;DR

This paper investigates how an external axial-vector field influences the chiral magnetic effect, revealing that the anomalous current is unaffected by the axial-vector background in the chiral limit.

Contribution

It provides an exact solution to the Dirac equation with external fields and shows that the axial-vector field does not directly contribute to the anomalous current in the chiral limit.

Findings

The axial-vector field does not contribute directly to the anomalous current.

Exact solutions for massive and chiral fermions in external fields are obtained.

Comparison with previous studies highlights the non-contribution of the axial-vector field.

Abstract

We study the excitation of the electric current of chiral fermions along the external magnetic field, known as the chiral magnetic effect, in the presence of the background axial-vector field. The calculation of the current is based on the exact solution of the Dirac equation for these fermions accounting for the external fields. First, this solution was obtained for massive particles and, then, we consider the chiral limit, which is used in the anomalous current computation. We obtain that, in this situation, the anomalous current does not contain the direct contribution of the axial-vector field. This result is compared with findings of other authors.