Rn. Hewitt et al., THE SCATTERING OF POSITRONS AND POSITRONIUM BY ATOMS IN THE CLOSE-COUPLING APPROXIMATION, Acta Physica Polonica. A, 88(1), 1995, pp. 139-145
We present some recent results obtained within the dose-coupling appro
ximation for both positron and positronium scattering by atoms. We beg
in by discussing a generalization of the method of Vincent and Phatak
to study the formation of Ps(-) in Ps collisions with H(ls) in a simpl
ified model. The important result of this calculation is that the over
all Coulomb interaction which is present in the rearrangement channel
is treated exactly. We also present results for positronium formation
and ionization for positron scattering by argon atoms. The present cal
culations are for transitions from the Ar(3s(2)) subshell and show the
importance of the coupling to the continuum.