Classical and semiclassical non-perturbative treatments of the electron transfer process in the collisional system proton-hydrogen involving initial excited states

We investigate the total cross sections of the electron transfer process in the proton-hydrogen collisional system involving initial excited states at impact energies in the 2.5 eV/u?100 keV/u range. The calculations are based on two non-perturbative treatments, namely the semiclassical atomic orbitals close-coupling (SC-AOCC) approach and the classical trajectory Monte Carlo method. The results are presented and discussed for the collisions taking into account the degeneracy of each level in orbital momentum ?. We find that the SC-AOCC results show empirical n 3 and n 4 scaling laws at low and high impact velocities, respectively.