Low-energy positron scattering by saturated and unsaturated hydrocarbons: Cross sections and bound states

We employed our recent version of the Schwinger multichannel method, implemented with a model potential [F. F. Frighetto, A. S. Barbosa, and S. d'A. Sanchez, Phys. Rev. A 108, 012818 (2023)] to calculate cross sections for elastic positron scattering by a set of hydrocarbons. Initially, by comparing the model potential calculations for methane, ethylene, and acetylene with our best possible ab initio calculations to date, we obtained the cutoff parameter for the carbon atom. Our results show that this parameter depends on the hybridization of the carbon atom for each molecule. We then applied the same cutoff parameter for the model potential to calculate the cross sections for other saturated and unsaturated hydrocarbons with encouraging results. We also discuss the positron binding to these hydrocarbons and compare the present results with available data from the literature.