Observation of elastic rotationally mediated critical kinematic selective adsorption in D2 scattering from Cu(001)

Elastic rotationally mediated critical kinematic selective adsorption (RMCK-SA) is reported in the scattering of D2 (j=0) from the Cu(001) surface. In a series of drift spectra taken for different surfaces temperatures between 40 and 500 K resonance lineshapes are observed which differ from the Lorentzian or Fano-type functions usually found in resonant scattering. The RMCK-SA effect results from the interaction among several diffraction and rotational channels. A theory is presented which gives resonance profiles in good agreement with experiment over the whole range of surface temperatures studied. From the best-fit of the experimental profiles a lifetime for the third bound state of the D2/Cu interaction potential of about 14×10−12 s is obtained.