Wolfgang Fritsch

Density matrix of the H (n = 2 and 3) atoms formed in electron capture process of p-He collisions using the AO + model

Abstract We have determined full density matrices of H ( n = 2 and 3) atoms formed after the electron capture in p-He collisions in the energy range 25–100 keV. An AO + method, in which pseudostates representing excitation and ionization channels are included in the usual two-center atomic-orbital (AO) expansion, is employed. The diagonal elements of the density matrix represent partial cross sections for a given n -manifold; the off-diagonal elements (which give coherences between degenerate states) are used to determine several first order moments (e.g., electric dipole moment) as a function of impact parameter and energy. The integrated (over impact parameter) moments are compared with recent experimental data on the n = 3 shell.