THEORETICAL-STUDIES OF ANTIHYDROGEN FORMATION IN COLLISIONS BETWEEN POSITRONIUM ATOMS AND ANTIPROTONS

The current state of the theoretical methods that are used in calculat ions of cross sections for the production of antihydrogen in collision s between antiprotons and positronium atoms is reviewed. A broad outli ne of available methods together with the results of recent computatio ns are presented. The main emphasis is made on the general close-coupl ing approach that allows any reaction channel to be taken as the initi al state of the collision system. In this way, and on account of charg e-conjugation invariance, the formation of antihydrogen in collisions between antiprotons and positronium atoms becomes linked to positron-h ydrogen scattering and the same computational methods can be applied t o either reaction. The review gives references to recent papers on the subject.