Triple Compton effect: A photon splitting into three upon collision with a free electron

TL;DR

This paper investigates the triple Compton effect, where a photon splits into three after colliding with a free electron, evaluating cross sections in realistic scenarios and confirming experimental feasibility.

Contribution

It provides the first calculation of the differential cross section for the triple Compton effect in two experimental setups, including gamma and keV photons with high-energy electrons.

Findings

Calculation agrees with existing measurements for gamma photons.

Process should be measurable with x-ray free electron lasers.

Quantifies polarization entanglement in the final state.

Abstract

The process in which a photon splits into three after the collision with a free electron (triple Compton effect) is the most basic process for the generation of a high-energy multi-particle entangled state composed out of elementary quanta. The cross section of the process is evaluated in two experimentally realizable situations, one employing gamma photons and stationary electrons, and the other using keV photons and GeV electrons of an x-ray free electron laser. For the first case, our calculation is in agreement with the only available measurement of the differential cross section for the process under study. Our estimates indicate that the process should be readily measurable also in the second case. We quantify the polarization entanglement in the final state by a recently proposed multi-particle entanglement measure.