Efficient translational excitation of a solid metal surface: State-to-state translational energy distributions of vibrational ground state HCl scattering from Au(111)

The authors report high resolution state resolved measurements of the translational inelasticity of HCl(v=0 -> 0,J=0 -> 4) colliding with a Au(111) surface at near normal incidence in the energy range of 0.28-1.27 eV. The translational inelasticity is large and indistinguishable from previous measurements for the HCl(v=2 -> 2,J=1 -> 5) channel. They discuss these observations in terms of an impulse approximation as well as the possible role of translational excitation of electron-hole pairs in the solid.