Optical-model Approach For Positronium Formation In Positron Scattering From H And Na Atoms

The optical-model approach has been used to investigate the Positronium formation process in positron collision with atoms. In present work we have successfully obtained an momentum-space equivalent local polarization potential describing the positronium formation rearrangement process (the real and virtue parts describe the virtue and real positronium formation respectively). The optical potential has been used to evaluate the total positronium formation cross section in the low energy (6.8eV-13.0eV) positron-hydrogen collision and the positronium (n=1,n=2) formation cross section in low-and intermediate-energy (0.1eV-20.0eV)positron-sodium collision, and the present results have also been compared with corresponding results of other theoretical models and the experimental measurements. At the same time, we also carried out the momentum space coupled channels optical method(CCO) for the positron scattering from hydrogen at low energies, the total cross section was reproduced and compared with other theoretical methods.