Schwinger pair creation of Kaluza-Klein particles: Pair creation without tunneling

TL;DR

This paper investigates the Schwinger pair creation process for Kaluza-Klein particles in a static electric field, revealing a non-tunneling mechanism involving the Unruh effect and vacuum polarization, despite gravitational backreaction preventing tunneling.

Contribution

It demonstrates that pair creation occurs without tunneling in a KK electric field, highlighting a novel mechanism involving the Unruh effect and vacuum polarization.

Findings

Pair creation rate similar to Schwinger's original result

Backreaction prevents tunneling over the potential barrier

Pair creation occurs via a different mechanism involving acceleration effects

Abstract

We study Schwinger pair creation of charged Kaluza-Klein particles from a static KK electric field. We find that the gravitational backreaction of the electric field on the geometry - which is incorporated via the electric KK Melvin solution - prevents the electrostatic potential from overcoming the rest mass of the KK particles, thus impeding the tunneling mechanism which is often thought of as responsible for the pair creation. However, we find that pair creation still occurs with a finite rate formally similar to the classic Schwinger result, but via an apparently different mechanism, involving a combination of the Unruh effect and vacuum polarization due to the E-field.