Electron-positron pair production during the collision of nonrelativistic charged particles

Pair production during the collision of nonrelativistic particles was investigated, starting from the discrepancy between theoretical predictions and experimental results. Projectile-target combinations with very different atomic charge and projectile energies just above the reaction threshold of 1.022 MeV were considered. The calculations show that at the threshold the pair production cross section is strongly reduced, such that the theoretical predictions are orders of magnitude below the experimental results.