Chiral magnetic effect in the presence of an external 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.

Comments: 13 pages in pdflatex, 2 pdf figures; paper was significantly revised, Sec. 4 was extended by the discussion of the applicability of chiral phenomena to neutron star physics; matches the version to be published in Phys.Rev.D