Electron-positron pair production in an arbitrary polarized ultrastrong laser field

TL;DR

This paper investigates how the polarization of ultrastrong laser fields affects electron-positron pair production, revealing that optimal pair generation often occurs with elliptical or circular polarization rather than linear, contrary to previous assumptions.

Contribution

It introduces a perturbative approach using Volkov states to analyze pair production in arbitrary polarized fields, highlighting the significant impact of polarization on production efficiency.

Findings

Optimal pair production depends strongly on polarization.

Elliptical and circular polarizations can outperform linear polarization.

Unexpected features in pair generation are discussed.

Abstract

Electron-positron pair production in an arbitrary polarized ultrastrong laser field is investigated in the first order perturbation approximation in which the Volkov states are used for convenient calculation of scattering amplitude and cross section. It is found surprisingly that the optimal pair production depends strongly on the polarization. For some cases of field parameters, the optimal field is elliptically polarized or evenly circularly polarized one, rather than the usual linear polarization as indicated by previous works. Some insights into pair generation are given and some interesting unexpected features are also discussed briefly.