Classical and near-classical origins of the oscillations in state- and angle-resolved inelastic scattering

We describe the results of a path integral study of state- and angle-resolved inelastic scattering utilising an extension of S-matrix theory. We demonstrate that interference effects, often thought to characterise wave-like behaviour, may result from the coincidence of classical and near-classical paths leading to the same molecular quantum state when scattered off a potential modelled as a hard ellipse. This indicates that the most refined of experimental scattering quantities may be viewed from the perspective, and with the clarity of, classical (and near-classical) mechanics, as may the more averaged of experimental molecular dynamics quantities. The success of this simple form of the intermolecular potential has implications concerning efforts to relate angular scattering parameters to fine details of the intermolecular potential.