POSITRON-HYDROGEN SCATTERING AT LOW ENERGIES

Calculations of positron-hydrogen scattering using the close-coupling approach are reported for incident positron energies below the ionizat ion threshold. The channel space includes nine physical hydrogen and p ositronium states and, in addition, eleven hydrogen and positronium ps eudostates. The accuracy of our model has been validated by computatio ns of elastic phase shifts below the positronium threshold, and elasti c and positronium-formation cross sections in the Ore gap. Calculation s are performed for sufficient partial waves to obtain converged elast ic, positronium, and total cross sections.