Effects of time evolution of coherently excited vibrations in molecular core—hole decay spectra of O2

Abstract Lifetime vibrational interference effects modulate the line shapes observed in high-resolution studies of the decay of ultra-short-lived core—hole excited states in molecules. We have analyzed the decay of the 1σ −1 u 1π 3 g core excited state in O 2 , where for the first time subsets of vibronic eigenfunctions could be selected. We demonstrate that this type of spectroscopy can be used to verify the predictions of quantum mechanical interference theory describing the time evolution of coherently excited vibrational states on the femtosecond time scale.