Vibrational excitation of ν '=1 and 2 levels of CO molecules by positron impact below the positronium formation threshold

Abstract

Reports vibrationally inelastic ( nu =0 to nu '=1 and 2) integral cross sections for positron-CO scattering below the positronium threshold. The fixed-nuclei approximation is employed in a single-centre approach. As expected, the final cross sections for the nu '=1 and 2 excitations are structureless with magnitudes of about (3-0.3)*10-17 cm2 and (4-0.15)*10-20 cm2 respectively, in the energy range from the vibrational excitation threshold up to the positronium formation threshold. The corresponding first Born results are in qualitative agreement throughout.