Triply differential photoelectron studies of resonances in molecular photoionization

Abstract

Shape and autoionizing resonances are central to the study of molecular photoionization for various reasons, the most obvious one being that they are usually displayed prominently against nonresonant behavior in such observables as the total photoionization cross section, photoionization branching ratios, and photoelectron angular distributions. More importantly, the study of resonant features has repeatedly led to a deeper physical insight into the mechanisms of excitation, resonant trapping of the photoelectron, and decay of the excited complex that occur during the photoionization process. A major impetus has been provided in this area by the ability to freely probe resonances throughout the ionization continuum with synchrotron radiation and to perform angle-resolved photoelectron spectrometry on the ejected electrons. Selected examples will serve to illustrate the recent progress and the prospects of this stream of work.