Schwinger effect for non-Abelian gauge bosons

TL;DR

This paper studies the Schwinger effect for non-Abelian gauge bosons like gluons, revealing particle production under color electric fields but not magnetic fields, with unique features due to confinement in QCD.

Contribution

It provides the first analysis of gluon production in non-Abelian backgrounds, highlighting differences from Abelian cases and the impact of confinement.

Findings

Gluons are produced in color electric fields but not in magnetic fields.

No exponential suppression due to gluon masslessness.

Critical field strength is larger in non-Abelian theories because of confinement.

Abstract

We investigate the Schwinger effect for the gauge bosons in an unbroken non-Abelian gauge theory (e.g. the gluons of QCD). We consider both constant "color electric" fields and "color magnetic" fields as backgrounds. As in the Abelian Schwinger effect we find there is production of "gluons" for the color electric field, but no particle production for the color magnetic field case. Since the non-Abelian gauge bosons are massless there is no exponential suppression of particle production due to the mass of the electron/positron that one finds in the Abelian Schwinger effect. Despite the lack of an exponential suppression of the gluon production rate due to the masslessness of the gluons, we find that the critical field strength is even larger in the non-Abelian case as compared to the Abelian case. This is the result of the confinement phenomenon on QCD.