Photon polarization effects in polarized electron-positron pair production in a strong laser field

TL;DR

This study uses polarization-resolved Monte Carlo simulations to analyze how photon polarization influences electron-positron pair production in strong laser fields, revealing significant polarization effects and yield reductions.

Contribution

It provides a detailed polarization-dependent analysis of pair production in strong-field QED, highlighting the impact of photon polarization on pair polarization and yield.

Findings

Pair polarization is reduced by 35% when photon polarization is resolved.

Pair yield decreases by approximately 13% due to polarization effects.

Positron polarization direction can be reversed in small angle regions.

Abstract

Deep understanding of photon polarization impact on pair production is essential for the efficient creation of laser driven polarized positron beams, and demands a complete description of polarization effects in strong-field QED processes. We investigate, employing fully polarization resolved Monte Carlo simulations, the correlated photon and electron (positron) polarization effects in multiphoton Breit-Wheeler pair production process during the interaction of an ultrarelativistic electron beam with a counterpropagating elliptically polarized laser pulse. We showed that the polarization of e^-e^+ pairs is degraded by 35\%, when the polarization of the intermediate photon is resolved, accompanied with an approximately 13\% decrease of the pair yield. Moreover, the polarization direction of energetic positrons in small angle region is reversed, which originates from the pair production of hard photons with polarization parallel with electric field.