Charge Fluctuations from the Chiral Magnetic Effect in Nuclear Collisions

TL;DR

This paper derives a nonlocal effective Lagrangian for the chiral magnetic effect and estimates charge asymmetry fluctuations in heavy ion collisions, finding them much smaller than experimental observations.

Contribution

It introduces a nonlocal effective Lagrangian for the chiral magnetic effect and provides quantitative estimates of charge fluctuations in nuclear collisions.

Findings

Charge asymmetry fluctuations are estimated to be less than 10^{-6}.

The predicted fluctuations are several orders of magnitude smaller than STAR experiment signals.

The study offers a theoretical framework for understanding charge fluctuations in heavy ion collisions.

Abstract

We derive a nonlocal effective Lagrangian for the chiral magnetic effect. An electric field is generated by winding number fluctuations of the nonabelian gauge field in the presence of a strong magnetic field. We estimate the magnitude of charge asymmetry fluctuations with respect to the reaction plane induced by the chiral magnetic effect in relativistic heavy ion collisions to be less than $10^{-6}$, several orders of magnitude smaller than the signal observed in the STAR experiment.