Positronium formation in positron-metastable-helium collisions - art. no. 012705

Positronium formation in the transfer-excitation reaction of positrons impa cting on singlet and triplet metastable He(1s2s) is studied at intermediate and high impact energies within the framework of a four-body version of th e continuum distorted wave-final state model. Cross sections for selective final states of the residual target as well as total cross sections and pol arization fraction of the 2p - 1s multiplet line of He+ are computed by usi ng a partial-wave technique. For 2p final states of He+ cross sections exhi bit interference patterns.