Antiproton Annihilation into Two Mesons and Higher Symmetries

The annihilation of antiprotons on nucleons is investigated assuming various symmetry groups. The general structure of the transition amplitude is found for the unitary symmetry and the higher symmetries SL (6, C) and U (6, 6) are applied to annihilations at rest. The relations between matrix elements, amplitudes and cross sections, following from various symmetries are compared with each other and with experiments. It is shown that all SL (6, C) predictions, that can be compared with experiments, are in good agreement, whereas the stronger results of the U (6, 6) symmetry contradict experiments.