Positronium collisions with ${\mathrm{O}}_{2}$ and ${\mathrm{CO}}_{2}$

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Positronium collisions with $O_{2}$ and ${CO}_{2}$

R. S. Wilde, H. B. Ambalampitiya, and I. I. Fabrikant

Phys. Rev. A 104, 012810 – Published 20 July 2021

Abstract

We calculate elastic and positronium (Ps) breakup cross sections for collisions of Ps with $O_{2}$ and ${CO}_{2}$ molecules in the fixed-nuclei approximation. We incorporate electron exchange and correlations for these processes by using the free-electron-gas model developed earlier for Ps scattering by rare-gas atoms and $N_{2}$ molecules. The results exhibit similarity between electron and Ps scattering when the cross section is plotted as a function of the projectile velocity, confirming experimental observations [S. J. Brawley et al., Science 330, 789 (2010)]. Below the Ps breakup threshold we observe resonance structures similar to those obtained earlier for Ps- $N_{2}$ scattering.