Positronium and antihydrogen formation in thee+-H and Ps-p¯ systems

The close coupling equations for the e+-H and Ps-p systems are solved for a model calculation comprising three hydrogen H(1s, 2s, 2p) and three positronium Ps(1s, 2s, Ps(1s), Ps(2s), and Ps(2p) states for e++H→Ps+p reaction achieves a peak of 2.7πa02 and is smaller than the only existing set of experimental data. The cross section for antihydrogen formation in the Ps+p→e+H reaction reaches a maximum of (13-14)πa02 for incident antiproton energies between 6.5 and 11 keV.