High energy photon production in strong colliding laser beams

The collision of two intense, low-frequency laser beams is considered. The $e^{-}{e}^{+}$ pairs created in this field are shown to exhibit recollisions, which take place at high energy accumulated due to the wiggling of fermions. The resulting $e^{-}{e}^{+}$ annihilation produces high energy photons, or heavy particles. The coherent nature of the laser field provides strong enhancement of the probability of these events. Analytical and numerical results are outlined.