Interference effects during the Auger decay of the C*O 1s-1π* resonance studied by angular distribution of the CO+(A) photoelectrons and polarization analysis of the CO+(A-X) fluorescence

Angular distributions of the CO+(A 2Π) photoelectrons and of the CO+(A 2Π→X 2Σ+) fluorescence are computed in the vicinity of the 1s-1π* resonant excitation of the C*O molecule. In the calculations, lifetime vibrational interference and the direct transition amplitude for population of the A 2Π(v') states were taken into account ab initio. The weak direct photoionization channel induces broad exciting-photon energy range dispersions of the angular distribution parameters βAe(ω) and β2AX(ω), and the nuclear vibrational motion causes variations of the computed parameters across the positions of the C*O(vr) vibronic states. Present calculations are in good agreement with available vibrationally and angularly resolved resonant Auger spectra. Theoretical β2AX(ω) parameters are in agreement with the experimental results from the polarization analysis of the CO+(A-X) fluorescence induced by linearly polarized synchrotron radiation.