Electron exchange model potential: Application to positronium-helium scattering

Abstract

The formulation of a suitable nonlocal model potential for electron exchange is presented, checked with electron-hydrogen and electron-helium scattering, and applied to the study of elastic and inelastic scattering and ionization of ortho positronium (Ps) by helium. The elastic scattering and the $n=2$ excitations of Ps are investigated using a three-Ps-state close-coupling approximation. The higher ($n\ge 3$) excitations and ionization of Ps atom are treated in the framework of Born approximation with present exchange. Calculations are reported of phase shifts, and elastic, Ps-excitation, and total cross sections. The present target elastic total cross section agrees well with experimental results at thermal to medium energies.

16 latex pages, 7 postscript figures

Cited by in corpus (18)

• Scattering of positronium by H, He, Ne, and Ar
• o-Positronium scattering off H and He
• Positronium atom scattering by H_2 in a coupled-channel framework
• Positronium-hydrogen-atom scattering in a five-state model
• Positronium-positronium interaction: Resonance, scattering length, and Bose-Einstein condensation
• Effect of H${}^{-}$ ion formation on Positronium-Hydrogen elastic scattering
• Convergent variational calculation of positronium-hydrogen-atom scattering lengths
• Low-energy quenching of positronium by helium
• Differential cross sections for elastic and inelastic positronium-hydrogen-atom scattering
• Calculations of positronium-atom scattering using a spherical cavity
• Differential and partial cross sections of elastic and inelastic positronium-helium-atom scattering
• Variational calculation of positronium-helium-atom scattering length
• S-, P- and D-wave resonances in positronium-sodium and positronium-potassium scattering
• Low-energy direct muon transfer from H to Ne${}^{10+}$, S${}^{16+}$ and Ar${}^{18+}$ using two-state close-coupling approximation to Faddeev-Hahn-type equation
• Positronium scattering by atoms and molecules at low energies
• Resonances in positronium-rubidium and positronium-cesium scattering
• Fragmentation of Positronium (Ps) in collision with Li ion
• Complete Break Up of Ortho Positronium (Ps)- Hydrogenic ion System