Configuration space method to calculate rearrangement matrix elements

Abstract

SynopsisA new method based on partial-wave expansion of the Ps radial wave functions has been developed for calculating the Ps-formation matrix elements. The method utilises the Euler-Wijngaarden tansformation to accelerate slowly converging series. The integrals in the method are free of the Coulomb singularity that appears in previously used momentum-space methods and therefore more straightforward to apply to complex and charged targets. The results are compared with the existing benchmark calculations for positron scattering on H and He+ targets.