Near-threshold photoionization of the Xe 3d spin-orbit doublet:: Relativistic, relaxation, and intershell interaction effects -: art. no. 022719

Results of calculations of the near-threshold photoionization of the xenon 3d spin-orbit doublet are reported. Our theoretical analysis is undertaken in order to interpret and enlighten the very detailed measurements of this process [A. Kivimaki , Phys. Rev. A 63, 012716 (2001)], which revealed a previously unobserved interesting feature-an additional broad maximum-in the partial xenon 3d(5/2) cross section. This double maximum was not produced by earlier calculations, except in the recent study by Amusia [Phys. Rev. Lett. 88, 093002 (2002)], which, in contrast to the present one, is not ab initio and relativistic in character. The partial photoionization cross sections of 3d(5/2) and 3d(3/2) subshells, photoelectron anisotropy parameters, and spin-polarization parameters that were so far not studied either experimentally or theoretically are calculated. Many-electron correlations, relativistic effects, and relaxation effects of the ionic core in the ionization process are taken into account by using the relativistic random-phase approximation, modified to include the relaxation of the considered subshell.