In a recent publication [D. Assafrão et al., Phys. Rev. A 84, 022713 (2011)] a model-potential approach was proposed to positron-atom scattering based on an adiabatic method that treats the positron as a light nucleus. In this paper the formalism is further improved by the introduction of semiempirical energy terms which appropriately account for the positron-target interaction at long and short ranges. Our method allows us to describe the main observed features of the elastic cross sections for positron scattering from He, Ne, Ar, Kr, and Xe. Valuable insights into the cross-section behavior below the positronium formation threshold, the scattering lengths, and other aspects of the low-energy positron-noble gases scattering are presented.

• Received 21 January 2013

DOI:https://doi.org/10.1103/PhysRevA.87.052702