Strong Dynamical Effects of Many-Electron Interactions in Photoelectron Spectra from 4s and 4p Core Levels

Dipolar fluctuations of 4 s and 4 p holes in the elements around Xe have been found to make a one-electron type of picture break down. This explains the failure of monopole relaxation, as included e.g. through the relativistic Hartree-Fock ΔSCF procedure, and shake off processes to describe ESCA spectra in this energy region. In Xe we find that neither a 4 p 1/2 nor a 4 p 3/2 hole can exist as an elementary excitation (quasi-stationary state) but become smeared over a large energy range. Instead, the most stable and probable state is found to belong to the Xe + (4 d 8 4 f ) 3/2 configuration and we identify this with the main ESCA peak at 145.5 eV. We also present a photo-electron spectrum for the 4 s and "4 p " region in quite good agreement with experiment.