Break-up of positronium (Ps) atom in collision with a He+ ion

Abstract

The dynamics of electron loss to the continuum (ELC) from the light neutral projectile positronium (Ps) atom in collision with He+ ion is studied in the framework of post-collisional Eikonal approximation. The full three-body interaction, which is crucial for such ELC process is taken into account in the final channel. Both the triple differential cross sections (TDCS) and the double differential cross sections (DDCS) are studied at some intermediate and high incident energies, with respect to the threshold energy for this process. A distinct broad ELC peak centred around ve (velocity of the ejected electron) ≈vp (velocity of the positron) is noted in the ejected electron energy spectrum (DDCS) for forward ejection of e/e+, corroborating the experimental findings for the ELC process. The probability of emission of the e+ at higher angles is almost negligible as compared to its forward emission. Another salient feature noted in the present work is the shifting of the ELC DDCS (summed over the electron ejection angles) peak towards higher value of the ratio ve/vp with increasing incident energy, in agreement with the experimental findings of Armitage et al for Ps–He break-up process.