Angle-resolved photoelectron spectrometry studies of the autoionization of the 2s(2)2p 2P triply excited state of atomic lithium: experimental results and R-matrix calculations

We have measured the angle-resolved energy dependence of the electrons emitted over the energy range of the triply excited 2s(2)2p 2P lithium resonance using synchrotron radiation. We have also calculated the behavior of the angular distribution parameter beta using the R-matrix approximation. Experimental and theoretical results are in good agreement and show deep minima in the 1s2p (1, 3)P ionic channels. The energy at which the minima occur does not coincide with the resonance energy, but is shifted towards higher energy.