Generalization of the duration-time concept for interpreting high-resolution resonant photoemission spectra

The experimental and theoretical investigations of the dynamics involved in the formation of resonant x-ray photoelectron (RPE) spectra at high-resolution were discussed. For selective excitations to different vibrational levels, the RPE spectra of the first three outermost singly ionized valence states was measured. It was found that the RPE profiles were asymmetrical as a function of frequency detuning. The results show that the duration time of the scattering process varies for different final electronic and different final vibrational states due to the competition between the fast 'vertical' and the slow 'resonant' scattering channels.