Momentum spectrum of Schwinger pair production in four-dimensional e-dipole fields

TL;DR

This paper calculates the momentum spectrum of electron-positron pairs produced by Schwinger mechanism in four-dimensional e-dipole electromagnetic fields, providing novel exact solutions relevant for experimental applications.

Contribution

It introduces the first calculation of the momentum spectrum for 4D exact Maxwell solutions, utilizing a new worldline instanton formalism for focused fields.

Findings

First momentum spectrum calculation for 4D Maxwell solutions

Development of a worldline instanton formalism for this context

Results relevant for future high-intensity laser experiments

Abstract

We calculate the momentum spectrum of electron-positron pairs created via the Schwinger mechanism by a class of four-dimensional electromagnetic fields called e-dipole fields. To the best of our knowledge, this is the first time the momentum spectrum has been calculated for 4D, exact solutions to Maxwell's equations. Moreover, these solutions give fields that are optimally focused, and are hence particularly relevant for future experiments. To achieve this we have developed a worldline instanton formalism where we separate the process into a formation and an acceleration region.