Positronium Formation in Positron-Hydrogen Scattering at Intermediate Energies
Recently, experiments1–3 have been performed to measure the positronium (Ps) formation cross section in positron-atom and positron-molecule scattering. The results of the University College London groupl differ drastically from those of the Texas group2. Moreover, the most recent findings of the Texas group3 show that their results in the case of e+- He scattering differ from first Born (FBA) predictions appreciably even at an incident positron energy of 250 eV. These observations have stimulated considerable theoretical activities4–6 along this line.