Relativistic and correlation effects in the anisotropy of near-threshold Kr 3d and Xe 4d photoionization

Angular distributions of the spin-orbit split components and their branching ratios have been studied experimentally and theoretically for the 3d photoelectrons of Kr and 4d photoelectrons of Xe. The focus was on the electron dynamics near the ionization threshold of each spin-orbit split component and its behaviour as a function of Z in passing from Kr to Xe. The experimental spectra were measured with high photon and electron energy resolutions with photon energies at about 3-12 eV above the 3d3/2 and 3d5/2 thresholds for Kr and at about 5-12 eV above the Xe 4d3/2 and 4d5/2 thresholds. Experimental results for the angular distribution parameters have been compared with theoretical values obtained with relativistic Dirac-Fock method and results from independent particle approximation with a modified Hartree potential [A. Derevianko, W. Johnson, K. Cheng, Atom. Data Nucl. Data Tables 73 (1999) 153]. The branching ratios were compared with theoretical predictions from Dirac-Fock and relativistic random-phase approximation [K. Cheng, W. Johnson, Phys. Rev. A 28 (1983) 2820].