Formation of protonium in the collision of antiproton with hydrogen atom

We carry out the quantum mechanical calculations of the total cross sections for the formation of protonium, for the first time within the intermediate energy range (50-250 keV) using the Born approximation. Two notable characteristics are considered. Firstly, unlike the case of electron capture by protons, here the differential cross sections increase slowly with the scattering angle. Secondly, for a heavy particle collision, usually the major contributions comes from below the angular region of the order of one milliradian (mrad.). But in the present case, contributions come from the entire angular region (00 - 1800) which is usually true for the light particle scattering. (author). 11 refs., 5 figs., 2 tabs