Positronium formation in positron-lithium collisions

Abstract

Differential and total cross sections have been studied for ground-state positronium (Ps) formation using the Glauber-eikonal approximation in positron-lithium atom collisions. The valence electron of the alkali-metal target and the effect of the core have been treated in the framework of a pseudopotential formalism. Results are reported for intermediate and high energies along with the first-order Born-approximation results. Even at very high energies the eikonal cross sections are found to be different from the corresponding first-order Born approximation showing the importance of higher-order effects.