Chiral Separation Effect from Holographic QCD

TL;DR

This paper investigates the chiral separation effect in QCD using holographic models, revealing how axial anomalies and radiative corrections influence the effect's conductivity across temperature and density variations.

Contribution

It introduces a holographic approach to analyze the chiral separation effect in QCD, accounting for axial anomalies and radiative corrections, and provides predictions at finite chemical potentials.

Findings

Qualitative agreement with lattice QCD results at small chemical potential and nonzero temperature.

Demonstrates the impact of axial gluon anomaly on CSE conductivity.

Provides predictions for CSE behavior at finite vectorial and axial chemical potentials.

Abstract

We analyze the chiral separation effect (CSE) in QCD by using the gauge/gravity duality. In QCD, this effect arises from a combination of chiral anomalies and the axial $U(1)$ anomaly. Due to the axial gluon anomaly, the value of the CSE conductivity is not determined by the anomalies of QCD but receives radiative corrections, which leads to nontrivial dependence on temperature and density. To analyze this dependence, we use different variants of V-QCD, a complex holographic model, carefully fitted to QCD data. We find our results for the anomalous CSE conductivity at small chemical potential and nonzero temperature to be in good qualitative agreement with recent results from lattice QCD simulations. We furthermore give predictions for the behavior of the conductivity at finite (vectorial and axial) chemical potentials.