Laser pulse-length effects in trident pair production

Abstract

Abstract Laser pulses facilitate multiphoton contributions to the trident pair production e L − → e L − + e L + + e L − , where the label L indicates a laser field dressed electron (e −) or positron (e + ). We isolate the impact of the pulse envelope in the trident S matrix element, formulated within the Furry picture, in leading order of a series expansion in the classical nonlinearity parameter a 0. Generally, the Fourier transform of the envelope carries the information on the pulse length, which becomes an easily tractable function in the case of a cos 2 pulse envelope. The transition to a monochromatic laser wave can be handled in a transparent manner, as also the onset of bandwidth effects for short pulses can be factorized out and studied separately.