Particle-beam scattering from strong-field QED

TL;DR

This paper studies how particles scatter off ultra-boosted, strong electromagnetic beams in QED, revealing that the scattering can be modeled as averaging over stochastic plane waves, challenging previous assumptions about strong-field effects.

Contribution

It introduces a non-perturbative method to analyze scattering in ultra-boosted strong fields by averaging over stochastic plane waves, providing new insights into strong-field QED behavior.

Findings

Scattering amplitudes are obtained by averaging over stochastic plane waves.

Ultra-boosted beams act as stochastic plane waves, not locally constant fields.

No strong-field QED behavior as previously conjectured is observed.

Abstract

We consider the scattering of probe particles on an ultra-boosted beam of charge, in the case that the fields of the beam are strong and must be treated non-perturbatively. We show that the fields of the ultra-boosted beam act as stochastic plane waves - scattering amplitudes (of elastic scattering, nonlinear Compton and nonlinear Breit-Wheeler) are obtained without approximation by averaging plane wave scattering amplitudes over all possible plane wave parameters. The relevant plane waves are ultra-short and, as such, scattering on ultra-boosted beams does not exhibit the conjectured strong-field behaviour of QED based on the locally constant field approximation.