Energy distributions of lepton pairs in ultra-intense laser and electrons collision

The energy distribution of positrons was investigated during the interaction of ultra-relativistic electrons with a petawatt-scale laser pulse. This study aims to elucidate the fundamental physics of lepton pair production by examining the interplay between two key mechanisms in the laser field: nonlinear Compton scattering and the nonlinear Breit-Wheeler process. Critical parameters, including laser intensity, electron energy, and collision geometry, were systematically analyzed to uncover the underlying principles governing positron production. The results demonstrate that the positron energy distribution is strongly influenced by the initial electron energy and the collision angle. The energy spectrum of positrons in the head-on collision scenario (θ=π) is an order of magnitude higher than that observed in small-angle collision (θ=4π/5). This significantly shapes its spectral characteristics. Furthermore, the observed spectra reveal distinct electron dynamics and cascade effects, providing insights into the complex behavior of particles in ultra-high electromagnetic fields. These findings offer valuable guidance for optimizing experimental setups to enhance positron production efficiency, with potential applications in advanced high-field physics research.