Resonance charge exchange between excited states in slow proton-hydrogen collisions

Abstract

The theory of resonance charge exchange in slow collisions of a proton with a hydrogen atom in the excited state is developed. It extends the Firsov-Demkov theory of resonance charge exchange to the case of degenerate initial and final states. The theory is illustrated by semiclassical and quantum calculations of charge exchange cross sections between states with $n=2$ in parabolic and spherical coordinates. The results are compared with existing close-coupling calculations.