Kinematically boosted pairs from the nonlinear Breit-Wheeler process in small-angle laser collisions

TL;DR

This paper proposes a nonperturbative scheme for pair production using high-energy photons in strong, converging laser fields, enhancing pair yield and enabling experimental exploration of quantum electrodynamics phenomena.

Contribution

It introduces a novel setup with small-angle laser collisions that boosts pair production from high-energy photons, highlighting the role of magnetic fields and above-threshold photons.

Findings

Pair yield increases for photon energies above 1.2m with converging laser pulses.

Magnetic fields in the setup contribute to nonperturbative pair production.

The scheme enables experimental study of spontaneous pair creation phenomena.

Abstract

We discuss a scheme of nonperturbative pair production by high energy photons ($\omega\gtrsim m$) in a strong external field achievable at the next high intensity laser experiments. The pair momentum is boosted and for $\omega\gtrsim 1.2m$ the pair yield is increased when the external field is formed by two laser pulses converging at a small angle. These characteristics are nonperturbative in origin and related to the presence of magnetic field in addition to electric field. By enhancing the signal over perturbative backgrounds, these features allow the employment of above-threshold photons $\omega>2m$, which further increases the pair yield. We note the close relation of this photon-pair conversion mechanism to spontaneous pair creation, recommending it as an accessible stepping stone experiment using state-of-the-art or soon-to-be laser technology.