Sphaleron damping and effects on vector and axial charge transport in high-temperature QCD plasmas

TL;DR

This paper studies how sphaleron transitions in high-temperature QCD plasmas influence charge transport phenomena, revealing a threshold wavenumber and damping effects that impact experimental signals of the Chiral Magnetic Effect.

Contribution

It introduces dissipative effects of sphaleron transitions into anomalous hydrodynamics and analyzes their impact on charge transport and wave phenomena in QCD plasmas.

Findings

Sphaleron transitions induce a wavenumber threshold for chiral magnetic waves.

Dissipative effects significantly alter the evolution of charge perturbations.

The vector charge separation depends on the sphaleron transition rate.

Abstract

We modify the anomalous hydrodynamic equations of motion to account for dissipative effects due to QCD sphaleron transitions. By investigating the linearized hydrodynamic equations, we show that sphaleron transitions lead to nontrivial effects on vector and axial charge transport phenomena in the presence of a magnetic field. Due to the dissipative effects of sphaleron transitions, a wavenumber threshold $k_{\rm CMW}$ emerges characterizing the onset of chiral magnetic waves. Sphaleron damping also significantly impacts the time evolution of both axial and vector charge perturbations in a QCD plasma in the presence of a magnetic field. Based on our analysis of the linearized hydrodynamic equations, we also investigate the dependence of the vector charge separation on the sphaleron transition rate, which may have implications for the experimental search for the Chiral Magnetic Effect in Heavy Ion Collisions.