Low-energy atomic scattering of ground-state C+(2P) ions by atomic hydrogen: role of non-adiabatic couplings and resonances in elastic and inelastic processes

The low-energy elastic and inelastic scattering of C + ( 2 P) by H( 2 S) is used as a model system to probe the dynamical ramifications of non-adiabatic couplings and resonances in open-shell-atom-open-shell-atom scattering. The authors briefly review the background theory of the influence of non-adiabatic interactions on open-shell-open-shell atomic collisions. The underlying dynamics and role of resonances are illustrated by presenting contributions from individual partial waves to the total cross section. This enables them to compare the resonance structure of the scattering cross sections with that for the photodissociation of CH + , both of which involve identical continua. The presence of phase differences between the multiple molecular states, correlating to a single elastic channel, is shown to produce the analogue of Stuckelberg-type oscillations in the partial elastic scattering cross sections. As expected, averaging over partial waves tends to wash out much of the interesting non-adiabatic resonance structure predicted for the CH + photodissociation cross section.