Positronium formation in positron-hydrogen scattering

The positronium-formation cross section in positron-hydrogen scattering has been calculated by using the distorted-wave approximation in which the total incident wave function is obtained by the method of polarized orbitals. The two variants of the polarized-orbital method, one due to Temkin and Lamkin and the other due to Callaway et al., have been employed to estimate their relative importance. The present results have been compared with those obtained by elaborate variational methods. The results obtained by using the potential of Temkin and Lamkin have been found to be encouraging