Hannover 2013 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 11: Quantum effects: QED
Q 11.7: Talk
Monday, March 18, 2013, 15:45–16:00, F 342
Pair production in short intense laser pulses near threshold — •Tobias Nousch1,2, Daniel Seipt1,2, Burkhart Kaempfer1,2, and Alexander I. Titov3 — 1Helmholtz-Zentrum Dresden-Rossendorf, POB 510119, 01314 Dresden, Germany — 2TU Dresden, Institut für Theoretische Physik, 01062 Dresden, Germany — 3Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna 141980, Russia
We study finite-size effects in the process of e+e− pair production via the non-linear Breit-Wheeler process in ultra short laser pulses. Based on the Nikishov-Ritus method we use laser dressed electron and positron wave functions to derive the differential and total pair production cross section, focusing on the effects of a finite pulse duration. For short laser pulses with very few oscillations of the electromagnetic field we find an increase of the pair production rate below the perturbative weak-field threshold. The strong enhancement below the weak-field threshold is traced back to the finite bandwidth of the laser pulse. A folding model accounts for the interplay of the frequency spectrum and the intensity distribution in the course of the pulse.