Fluid/gravity model for the chiral magnetic effect

TL;DR

This paper uses a holographic fluid/gravity model to analyze the chiral magnetic and vortical effects in strongly-coupled plasmas, providing calculations of related transport coefficients relevant to heavy ion collisions.

Contribution

It introduces a holographic model based on the STU gravity dual to describe chiral effects and computes associated transport coefficients using fluid/gravity duality.

Findings

Calculated chiral magnetic and vortical transport coefficients.

Identified analogous effects in the axial current.

Discussed late-time dynamics of expanding plasma with CME/CVE.

Abstract

We consider the STU model as a gravity dual of a strongly-coupled plasma with multiple anomalous U(1) currents. In the bulk we add additional background gauge fields to include the effects of external electric and magnetic fields on the plasma. Reducing the number of chemical potentials in the STU model to two and interpreting them as quark and chiral chemical potential, we obtain a holographic description of the chiral magnetic and chiral vortical effects (CME and CVE) in relativistic heavy ion collisions. These effects formally appear as first-order transport coefficients in the electromagnetic current. We compute these coefficients from our model using fluid/gravity duality. We also find analogous effects in the axial current. Finally, we briefly discuss a variant of our model, in which the CME/CVE is realized in the late-time dynamics of an expanding plasma.