Angle-dependent pair production in the polarized two-photon Breit-Wheeler process

TL;DR

This paper investigates how the polarization and angle dependence of photon collisions influence pair production in high-intensity laser-driven environments, revealing angle-dependent yields and polarization effects through analytical and simulation methods.

Contribution

It introduces a new spin basis for analyzing polarized pair production, enabling detailed understanding of angle-dependent polarization effects in the Breit-Wheeler process.

Findings

Photon polarization induces angle-dependent pair yields.

The new spin basis decouples transverse and longitudinal spin components.

Analytical and Monte Carlo methods reveal polarization effects.

Abstract

The advent of laser-driven high-intensity $\gamma$-photon beams has opened up new opportunities for designing advanced photon-photon colliders. Such colliders have the potential to produce a large yield of linear Breit-Wheeler (LBW) pairs in a single shot, which offers a unique platform for studying the polarized LBW process. In our recent work [Phys. Rev. D 105, L071902(2022)], we investigated the polarization characteristics of LBW pair production in CP $\gamma$-photon collisions. To fully clarify the polarization effects involving both CP and LP $\gamma$-photons, here we further investigate the LBW process using the polarized cross section with explicit azimuthal-angle dependence due to the base rotation of photon polarization vectors. We accomplished this by defining a new spin basis for positrons and electrons, which enables us to decouple the transverse and longitudinal spin components of $e^\pm$. By means of analytical calculations and Monte Carlo simulations, we find that the linear polarization of photon can induce the highly angle-dependent pair yield and polarization distributions. The comprehensive knowledge of the polarized LBW process will also open up avenues for investigating the higher-order photon-photon scattering, the laser-driven quantum electrodynamic plasmas and the high-energy astrophysics.