Pair Creation in Electric Flux Tube and Chiral Anomaly

TL;DR

This paper analyzes how massless fermions are produced in an electric flux tube with a magnetic field using chiral anomaly, revealing the decay dynamics of the electric field relevant to high-energy heavy-ion collisions.

Contribution

It provides an analytical study of fermion pair creation in an electric flux tube with magnetic field, highlighting the dependence of decay time on the tube's width and applying results to glasma decay.

Findings

Electric field lifetime decreases with narrower flux tubes.

Fermion number density and magnetic field behavior are analytically characterized.

Electric field decays on a timescale inversely proportional to saturation momentum Q_s.

Abstract

Using chiral anomaly, we discuss the pair creation of massless fermions under the effect of magnetic field $\vec{B}$ when an electric flux tube $\vec{E}$ parallel to $\vec{B}$ is switched on. The tube is axial symmetric and infinitely long. In the limit $B\gg E$, we can analytically obtain the spatial and temporal behaviors of the number density of the fermions, the azimuthal magnetic field generated by the fermions etc.. We find that the life time $t_c$ of the electric field is shorter as the width of the tube is narrower. Applying it to the glasma in high-energy heavy-ion collisions, we find that color electric field decays fast such as $t_c\simeq Q_s^{-1}$ with saturation momentum $Q_s$.