Pair Production Beyond the Schwinger Formula in Time-Dependent Electric Fields

TL;DR

This paper explores electron-positron pair production in time-dependent electric fields, revealing that in certain pulse regimes, pair yields surpass Schwinger predictions, and demonstrates agreement between quantum kinetic and effective action methods.

Contribution

It introduces a non-Markovian quantum kinetic framework to analyze pair production beyond the Schwinger formula in pulse-shaped fields, highlighting nonperturbative effects.

Findings

Pair production exceeds Schwinger estimates in specific pulse regimes.

Quantum kinetic and effective action approaches show remarkable agreement.

Identifies a pulse-length range where nonperturbative effects dominate.

Abstract

We investigate electron-positron pair production in pulse-shaped electric background fields using a non-Markovian quantum kinetic equation. We identify a pulse-length range for subcritical fields still in the nonperturbative regime where the number of produced pairs significantly exceeds that of a naive expectation based on the Schwinger formula. From a conceptual viewpoint, we find a remarkable quantitative agreement between the (real-time) quantum kinetic approach and the (imaginary-time) effective action approach.