STRUCTURES AT INTERMEDIATE ENERGIES IN POSITRON-HYDROGEN SCATTERING

We have confirmed the existence of a resonance shape around 35.6 eV, previously found by Higgins and Burke, in the S-wave positronium formation cross sections, that we calculated also within the coupled-static approximation but with the use of the Harris-Nesbet variational method. Still within the spirit of the coupled-static approximation, we added the polarization effects to the process by including the pseudo-state ($$$) over bar 2p in the coupling scheme, and found a whole range of structures formed at this intermediate energy region of the positronium formation cross sections. These structures were also seen in the elastic cross sections. We discussed the formation of these structures.