Threshold Excitation of Short-Lived Atomic Inner-Shell Hole States with Synchrotron Radiation

The Xe $L_3-M_4{M}_5 \left({}_{}{}^1{}_{}{}^{}G_4^{}{}_{}{}^{}\right)$ Auger spectrum, photoexcited in the vicinity of the $L_3$ edge, has been measured as a function of photon energy. The $\mathrm{nd}$ spectator-electron satellite lines show resonant behavior. The diagram line exhibits the larges (≳ 1 eV) post-collision interaction shift yet observed. For comparison with the data, the first fully quantum-mechanical calculation of the post-collision interaction in deep inner-shell Auger decay is performed, based on a resonant-scattering approach that involves a complete summation over intermediate $L_3$ one-hole states.