ANGULAR ANISOTROPY IN THE RESONANT AUGER DECAY OF 2P-PHOTOEXCITED MG

We have measured strongly negative beta values of the 3s-participator lines at the magnesium 2pi-->4s and 2p(1/2)-->3d excitations. Observed beta values of the spectator lines following 2pi-->4s excitation are not reproduced by the strict spectator model. Our multiconfiguration D irac-Fock calculations show that the resonant Auger spectra are influe nced by unusually pronounced configuration interaction in the excited state. This influence is strongly enhanced by a change of sign in the Auger amplitude of the leading term near the transition energy, a dyna mic effect similar to a Cooper minimum in photoionization.