Positronium collisions with polar molecules

Authors

R. S. Wilde
M. K. Selvage, Oregon Institute of Technology
Ilya I. Fabrikant, University of Nebraska-LincolnFollow

Date of this Version

9-19-2022

Citation

PHYSICAL REVIEW A 106, 032810 (2022). DOI: 10.1103/PhysRevA.106.032810

Comments

Used by permission.

Abstract

We calculate elastic and positronium (Ps) break-up cross sections for collisions of Ps with the polar molecules CO, HCl, and LiF in the fixed-nuclei approximation. We incorporate electron exchange and correlation for these processes by using the free-electron-gas model developed earlier for Ps scattering by rare-gas atoms, N₂, O₂, and CO₂ molecules. The present target molecules provide a range of dipole moments from the weakly polar CO to the strongly polar LiF. We find that Ps scattering is similar to electron scattering when the cross sections are plotted as a function of projectile velocity for the targets with smaller dipole moments (CO, HCl). However, we do not see such a similarity for LiF which has a large dipole moment. Below the Ps break-up threshold we observe resonance structures similar to those obtained earlier for the other molecular targets that we have studied.