Theoretical study of low-energy positron scattering on alkaline-earth atoms in the relativistic polarized orbital approximation

(Received 6 October 1992, accepted in final form 2 December 1992)

Abstract
The elastic low-energy positron scattering on Be, Mg, Ca, Sr, Ba and Ra atoms has been investigated at energies below 100 eV. The ab initio calculated polarization potentials applied in these calculations were obtained by solving the coupled Dirac-Hartree-Fock equations. Comparison between present results and those of previous model calculations shows serious discrepancies. Particularly, we do not predict existence of the Ramsauer-Townsend minima in total elastic cross sections.