Exact results for scattering on ultra-short plane wave backgrounds

TL;DR

This paper provides exact analytical results for scattering processes in ultra-short, ultra-intense plane wave backgrounds, revealing a logarithmic intensity scaling contrary to previous conjectures of power-law behavior.

Contribution

It offers the first closed-form expressions for emission spectra in delta-function modeled ultra-short pulses, challenging existing assumptions about perturbation theory breakdown.

Findings

Probabilities scale logarithmically with intensity at high values

Exact formulas for nonlinear Breit-Wheeler and Compton scattering

Contradicts previous power-law scaling conjectures

Abstract

We give exact results for the emission spectra of both nonlinear Breit-Wheeler pair production and nonlinear Compton scattering in ultra-intense, ultra-short duration plane wave backgrounds, modelled as delta-function pulses. This includes closed form expressions for total scattering probabilities. We show explicitly that these probabilities do not exhibit the power-law scaling with intensity associated with the conjectured breakdown of (Furry picture) perturbation theory, instead scaling logarithmically in the high-intensity limit.