Production of Electron Pairs from a Zero-Mass State

Results are presented for the production of electron pairs by the collision of high-energy bremsstrahlung and high-intensity laser beams. With Stanford linear accelerator bremsstrahlung parameters, it is found that the laser must be focused to about 10¹⁸ W/cm² to produce pairs. Approximately 25 laser photons participate in each event, and the required laser intensity is outside the known radius of convergence of perturbation theory for this process. The electron mass shift may also be determined.