Observation of Vibrational Excitation and Deexcitation for NO $(\mathit{v}=2\mathrm{})$ Scattering from Au(111): Evidence for Electron-Hole-Pair Mediated Energy Transfer

Measurements of vibrational excitation and deexcitation of NO $(v=2\mathrm{})$ scattering from a Au(111) surface show that the probability of both processes increases strongly with the kinetic energy of the incident NO. These results are qualitatively consistent with a vibrational energy transfer mechanism involving electron-hole pairs but not with competing adiabatic models. The form of the energy dependence, and other features of the measurements, are not in accord with existing calculations.