Finite size effects in stimulated laser pair production

Understand

We consider stimulated pair production employing strong-field QED in a high-intensity laser background.

• In an infinite plane wave, we show that light-cone quasi-momentum can only be transferred to the created pair as a multiple of the laser frequency, i.e.\ by a higher harmonic.
• This translates into discrete resonance conditions providing the support of the pair creation probability which becomes a delta-comb.
• These findings corroborate the usual interpretation of multi-photon production of pairs with an effective mass.