Chiral magnetic effect and holography

TL;DR

This paper provides a holographic model to describe the chiral magnetic effect in strongly-coupled plasmas, calculating related transport coefficients and exploring anisotropic effects linked to elliptic flow.

Contribution

It introduces a holographic fluid-gravity model for the CME with multiple anomalous U(1) currents, and computes the associated transport coefficient at strong coupling.

Findings

Holographic computation of the CME transport coefficient matches hydrodynamic predictions.

The model reveals potential dependence of the CME on anisotropic flow parameters.

First-order transport coefficient for the vector current is derived holographically.

Abstract

The chiral magnetic effect (CME) is a highly discussed effect in heavy-ion collisions stating that, in the presence of a magnetic field B, an electric current is generated in the background of topologically nontrivial gluon fields. We present a holographic (AdS/CFT) description of the CME in terms of a fluid-gravity model which is dual to a strongly-coupled plasma with multiple anomalous U(1) currents. In the case of two U(1) charges, one axial and one vector, the CME formally appears as a first-order transport coefficient in the vector current. We will holographically compute this coefficient at strong coupling and compare it with the hydrodynamic result. Finally, we will discuss an anisotropic variant of the model and study a possible dependence of the CME on the elliptic flow coefficient v_2.