Algebraic Close-Coupling Calculation of the Scattering of Electrons and Positrons by Hydrogen

Abstract

The algebraic close-coupling method is applied to slow collisions of electrons and positrons with atomic hydrogen. The wave function is assumed to be of the form appropriate for a $1s-2s-2p$ close-coupling calculation. The variational method proposed by Nesbet is used to calculate the appropriate phase shifts and cross sections. Excellent agreement with previously published results of Burke, Schey, Smith, and others is obtained for scattering below the $n=2\mathrm{}$ threshold. Information concerning resonance structure for positrons, and for electrons in the singlet and triplet state, is also obtained. Good results are also obtained above threshold in the $1s-2s$ and three-state approximations. Problems connected with the choice of asymptotic functions for the open $n=2\mathrm{}$ channels are discussed.