Transverse spreading of electrons in high-intensity laser fields

TL;DR

This paper demonstrates that quantum photon emissions during high-intensity laser-electron collisions cause a measurable transverse electron beam spread, distinct from classical effects, serving as a signature of strong-field quantum electrodynamics.

Contribution

It reveals a quantum-induced transverse momentum spread in electrons due to photon emissions, supported by numerical simulations with realistic laser parameters.

Findings

Quantum photon emissions cause transverse beam spread.

The effect is observable with current laser technology.

The transverse spread is a signature of strong-field QED.

Abstract

We show that for collisions of electrons with a high-intensity laser, discrete photon emissions introduce a transverse beam spread which is distinct from that due to classical (or beam shape) effects. Via numerical simulations, we show that this quantum induced transverse momentum gain of the electron is manifest in collisions with a realistic laser pulse of intensity within reach of current technology, and we propose it as a measurable signature of strong-field quantum electrodynamics.