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 H + + H ( n = 1 , 2 , 3 ) taking into account the degeneracy of each level in orbital momentum . We find that the SC-AOCC results show empirical n3 and n4 scaling laws at low and high impact velocities, respectively.