Positron-impact ionization of atoms and molecules

This paper presents the level of agreement between theory and experiment for positron-impact ionization of atoms and molecules. Distorted-wave theoretical models are able to reproduce the experimental integrated cross sections for atoms and diatomic molecules. The ECC phenomenon seen in the experimental triple differential cross sections can be obtained with a BBK-type model, but for very low impact energies the theory requires the inclusion of the coupling with the positronium formation channel.