Matrix elements for photoionization in xenon derived from coincidence electron spectrometry

The magnitudes and relative phases of the matrix elements pertaining to photoionization in xenon at 132.2 eV photon energy have been derived from observables in an angle-resolved electron spectrometry experiment. The observables in question are the partial cross section, the angular distribution parameter of the photoelectron, the alignment parameter of the photoion, and the angular correlation between the photoelectron and the coincident Auger electron. Difficulties in extracting the desired matrix elements from these observables are discussed. Despite these difficulties, a set of matrix elements and relative phases could be extracted which is in good agreement with all experimental observables and also fulfils the constraint that spin - orbit effects in the photoelectron's partial waves be negligible. This data set differs significantly from theoretical predictions from relativistic random-phase calculations.