S-wave positron scattering by hydrogen atoms

Abstract

The S-wave scattering of positrons by hydrogen atoms is studied using the coupled static approximation with 26 correlation functions for energies up to the excitation threshold of hydrogen. Up to a certain energy, the formulation satisfies a bound principle. Below the positronium formation threshold, the calculated phase shifts are very close to those of Bhatia et al (1971). Above this threshold, the R matrix elements and the cross sections are very different from those of other earlier calculations. No resonances were detected in a search with energy spacing of about 0.02 eV over the region just below the excitation threshold.