Ionization in Ps-H scattering

Abstract

Coulomb–Born approximation has been used to study three different types of ionization in positronium (Ps) and hydrogen scattering. The present Ps–H system contains four centers; we have considered all the Coulomb interactions and neglected exchange assuming the fact that at relatively higher energies above thresholds, the effect of exchange is not so important. All the important target elastic and inelastic channels are included. The non-unitarity problem in the target elastic channels, discussed by McAlinden et al. in 1996 in their positronium–atom scattering studies is overcomed in the present calculation using the orthonormality properties of target wavefunctions and a simple algebra. Comparative studies are made among ionization cross sections with different target excitations and different Ps-excitations together with summed Ps-ionization, summed H-ionization, both-ionization, summed excitation, total ionization and total cross sections. The present Letter indicates the importance of all the three different types of ionization and the importance of target elastic channels in Ps–H scattering.