PONTECORVO REACTIONS OF 2-BODY ANTIPROTON ANNIHILATION IN DEUTERIUM WITH VARIOUS MESONS IN THE FINAL-STATE

Rare annihilation reactions for stopped antiprotons in deuterium, (p) over bar d --> MN (where M = pi, eta, eta', rho, omega, phi, and a(0)) , are considered on the basis of the nonrelativistic two-step model de scribed by the triangle diagram. Since the probabilities of these reac tions are very sensitive to the cutoff in the virtuality of exchanged mesons, we determine the cutoff parameter Lambda by fitting the branch ing ratio for the reaction (p) over bar d --> pi(-)p. Subsequently, th e relative yields from other reactions are calculated and compared wit h available data. Despite the fact that, in some cases, the model give s reasonable estimates of branching ratios, it is clear that attempts at incorporating all effects of the quark-gluon degrees of freedom int o a single cutoff parameter cannot be considered to be successful.