Strong-field Breit-Wheeler pair production in $\mathrm{QED}_{2+1}$

TL;DR

This paper explores how the dimensionality of spacetime affects Breit-Wheeler pair production, revealing unique behaviors in 2+1 dimensions that differ from higher dimensions, with implications for perturbation theory validity.

Contribution

It provides the first analysis of Breit-Wheeler pair production in 2+1 dimensions, highlighting the effects of reduced dimensionality on production rates and perturbation theory.

Findings

Non-vanishing rates at energy threshold with odd photon numbers in perturbative regime

Distinct rate dependence on quantum non-linearity parameter in strong field regime

Potential breakdown of perturbation theory due to superrenormalizability in 2+1D QED

Abstract

The Breit-Wheeler pair production process in $2+1$ dimensional spacetime is investigated. In the perturbative regime, non-vanishing rates at the energy threshold are found when odd numbers of photons take part on the reaction. This behaviour is understood as a direct consequence of the reduced dimensionality and resembles a corresponding prediction made in gapped graphene monolayers. In the non-perturbative strong field regime the effect of the dimensionality manifests itself in a different rate dependence on the quantum non-linearity parameter. The consequence of this deviation is discussed briefly in line with the applicability of perturbation theory. We argue that, in addition to large values of the quantum non-linearity parameter, the superrenormalisable character of quantum electrodynamics in $2+1$ dimensional spacetime might give rise to a breakdown of perturbation theory within certain energy scales.