Close coupling calculations of positron-hydrogen scattering at low energies

Abstract

Calculations of low energy positron-hydrogen scattering using the close coupling approach are reported at low energies. Calculations are performed with six and twelve state basis sets which include physical states and pseudostates for both atomic hydrogen and positronium. For energies below the positronium formation threshold, phaseshifts are reported for J=0, 1, 2, 3 and 4 and found to agree with previous variational calculations to better than 0.01 rad. Total elastic and positronium formation cross sections are reported at four energies in the Ore gap. The J=0, 1 and 2 partial cross sections from the present calculations agree with earlier partial cross sections computed using variational techniques.