Multielectron excitations in theL-subshell photoabsorption of xenon

Multielectron excitations in x-ray absorption of xenon in the energy region of the L edges are studied. Broad structures in the subshell absorption spectra are attributed to virtual collective excitations such as core relaxation and dielectric polarization. Three groups of sharp spectral features, corresponding to multielectron transitions involving 5p, 5s, and 4d electrons, respectively, are found. Due to the large lifetime width and multiplet spread, the features are superpositions of individual transitions within a group. From comparison of corresponding features in the three L-subshell spectra, some conclusions on the role of the inner-shell vacancy in the process can be drawn. Differences in ${\mathit{L}}_1$ and ${\mathit{L}}_{2,3}$ spectral features generally point to a complex excitation mechanism, although some cases seem to obey the simple sudden approximation. Evidence for a strongly coupled outer-shell excitation involving the 4d subshell is found.