Pulse envelope effects in nonlinear Breit-Wheeler pair-creation
Abstract
The effect of the pulse envelope on electron-positron pair creation in a circularly-polarised laser pulse is investigated. Interference on the length scale of the pulse envelope, and smoothness of the pulse edges are found to influence the pair spectrum. A toy model of a flat-top pulse is used to identify pulse envelope effects inaccessible to local approaches. Broadening of channel openings and a widening of the energy and transverse momentum distribution of the pair are found to receive contributions that are below the local harmonic threshold. By comparing pair yields in a flat-top, sine-squared and Gaussian pulse, a link between pulse shape and photon-polarised Breit-Wheeler is found. In the transverse momentum distribution, a signal of pulse envelope interference is found in an azimuthal asymmetry, which appears in intense fields and persists in long pulses.
Keywords
Cite
@article{arxiv.2109.00555,
title = {Pulse envelope effects in nonlinear Breit-Wheeler pair-creation},
author = {S. Tang and B. King},
journal= {arXiv preprint arXiv:2109.00555},
year = {2021}
}
Comments
11 pages, 9 figures