Recent advances in relativistic excitation of atomic hydrogen

Within the framework of the relativistic regime (Ek>2700 eV) and the first Born approximation, we investigate the inelastic excitation of atomic hydrogen by electron impact from 1s to 2p state. The incoming and outgoing electrons are described by free Dirac spinors, while the hydrogen atom target is described by the exact solutions of Dirac equation with a central potential. A detailed study has been devoted to the non-relativistic regime as well as the relativistic regime of the process, and the results obtained show the differences between the two regimes. These differences have revealed that the differential cross section (DCS) is influenced by the parameters of the 1s and 2p states, along with significant effects on diffusion during small pulse transfers. The relativistic effects are responsible for the significant changes in the DCS as a function of diffusion angles which depend on the chosen geometry.