Angular-Resolved Molecular Photoionization

The interferences between different transition amplitudes of resonant photoionization and direct photoionization, known as 'electronic states interference (ESI)', and between transition amplitudes via different overlapping vibrational levels of the same electronic state, known as 'lifetime vibrational interference' (LVI) are studied both, theoretically and experimentally. The 1s-π* resonant core excitation and subsequent Auger decay of the N2, CO and NO molecules populating coherently different vibrational states of molecular ion decaying further via fluorescence emission are taken as the objects of the study. It is obtained that even for well separated vibronic resonances exhibiting very weak LVI in the total cross sections, the LVI gives rise to clearly observable variations of angular distribution parameters across the resonances. The ESI between the amplitudes for excitation and decay of neighboring electronic resonances of different symmetries plays a crucial role in their angularly resolved decay spectra, although it is strictly symmetry-forbidden in the solid-angle-averaged spectra. Results of calculations are verified by the recent photon-induced fluorescence spectroscopy (PIFS) experiments.

Cooperations: Prof. Dr. A. Ehresmann (University of Kassel, Germany),
Prof. Dr. K. Ueda (Tohoku University, Sendai, Japan), Prof. Dr. V.L. Sukhorukov,
Prof. Dr. I.D. Petrov and Prof. Dr. B.M. Lagutin (Rostov State University of Transport Communications, Rostov-on-Don, Russia)
Status: in progress