Application of the diagonalization approximation to then=3 resonant photoionization of helium-like systems

Abstract

A further analysis of the diagonalization approximation applied to multichannel resonant photoionization of two-electron systems near then=3 threshold of reduced hydrogenic ions is made here. We obtained excitation energies, partial and total eigenwidths of a few1p(−) and3p(−) low-lying resonances in He and some He-like ions. Comparison of our calculations with experimental data and with the results obtained using other approximations, like close-coupling calculations, enables the applicability of the diagonalization approximation for solving the multichannel resonant photoionization problem to be assessed.