Particle dynamics and spatial $e^-e^+$ density structures at QED cascading in circularly polarized standing waves

TL;DR

This paper investigates particle drift and electron-positron density structures in QED cascades within circularly polarized standing waves at extreme intensities, highlighting the effects of quantum radiation reaction and polarization on plasma formation.

Contribution

It provides a comparative analysis of radiation reaction models and reveals how polarization influences particle dynamics and plasma structures in QED cascades.

Findings

Circular and linear polarization lead to qualitatively different particle dynamics.

Quantum radiation reaction significantly affects electron-positron density structures.

3D PIC simulations confirm diverse pair plasma formations.

Abstract

We present a comprehensive analysis of longitudinal particle drifting in a standing circularly polarized wave at extreme intensities when quantum radiation reaction (RR) effects should be accounted for. To get an insight into the physics of this phenomenon we made a comparative study considering the RR force in the Landau-Lifshitz or quantum-corrected form, including the case of photon emission stochasticity. It is shown that the cases of circular and linear polarization are qualitatively different. Moreover, specific features of particle dynamics have a strong impact on spatial structures of the electron-positron ($e^-e^+$) density created in vacuum through quantum electrodynamic (QED) cascades in counter-propagating laser pulses. 3D PIC modeling accounting for QED effects confirms realization of different pair plasma structures.