Laser assisted Breit-Wheeler and Schwinger processes

TL;DR

This paper investigates how intense optical laser pulses influence electron-positron pair production via Breit-Wheeler and Schwinger processes in XFEL fields, revealing phase space redistribution and sensitivity to pulse shape.

Contribution

It provides a detailed analysis of laser-assisted pair production mechanisms and numerical examples for differential cross sections relevant to European XFEL parameters.

Findings

Laser pulses cause phase space redistribution of pairs in Breit-Wheeler process.

Schwinger pair production is affected by pulse shape and oscillating components.

Residual phase space distribution varies significantly with pulse parameters.

Abstract

The assistance of an intense optical laser pulse on electron-positron pair production by the Breit-Wheeler and Schwinger processes in XFEL fields is analyzed. The impact of a laser beam on high-energy photon collisions with XFEL photons consists in a phase space redistribution of the pairs emerging in the Breit-Wheeler sub-process. We provide numerical examples of the differential cross section for parameters related to the European XFEL. Analogously, the Schwinger type pair production in pulsed fields with oscillating components referring to a superposition of optical laser and XFEL frequencies is evaluated. The residual phase space distribution of created pairs is sensitive to the pulse shape and may differ significantly from transiently achieved mode occupations.