Polarization operator approach to pair creation in short laser pulses

TL;DR

This paper develops a theoretical framework using the polarization operator approach to calculate electron-positron pair creation probabilities in short, intense laser pulses, incorporating radiative corrections and pulse shape effects.

Contribution

It provides compact expressions for pair creation probability in arbitrary plane-wave fields and analyzes the impact of pulse shape and phase, advancing strong-field QED calculations.

Findings

Pair creation probabilities of about 10% are achievable with current technology.

Derived explicit formulas for pair creation in arbitrary plane-wave backgrounds.

Analyzed effects of laser pulse shape and carrier-envelope phase on pair production.

Abstract

Short-pulse effects are investigated for the nonlinear Breit-Wheeler process, i.e. the production of an electron-positron pair induced by a gamma photon inside an intense plane-wave laser pulse. To obtain the total pair-creation probability we verify (to leading-order) the cutting rule for the polarization operator in the realm of strong-field QED by an explicit calculation. Using a double-integral representation for the leading-order contribution to the polarization operator, compact expressions for the total pair-creation probability inside an arbitrary plane-wave background field are derived. Correspondingly, the photon wave function including leading-order radiative corrections in the laser field is obtained via the Schwinger-Dyson equation in the quasistatic approximation. Moreover, the influence of the carrier-envelope phase and of the laser pulse shape on the total pair-creation probability in a linearly polarized laser pulse is investigated, and the validity of the (local) constant-crossed field approximation analyzed. It is shown that with presently available technology pair-creation probabilities of the order of ten percent could be reached for a single gamma photon.