Rho rho/sup -/ annihilation into pi/sup +/ pi/sup -/ pi/sup 0/ in a hadron-exchange model

Abstract

Proton-antiproton annihilation into three pions is studied in a hadron-exchange model. An uncorrelated three-pion channel is added to the two-meson channels considered in previous calculations. Initial-state interactions are taken into account in a distorted-wave Born approximation, using the most complete version of the Jiilich NN model. The uncorrelated three-pion channel adds a 10% contribution to the pp pi/sup +/ pi/sup -/ pi/sup 0/ ative branching ratios for annihilation into three uncorrelated pions from states of equal orbital angular momentum, but different total angular momentum and spin, are also calculated. They compare semi-quantitatively with the corresponding quantities calculated from the phase-space components of phenomenological amplitudes fitted to experimental data for stopped antiprotons. It is concluded that hadron exchange provides a viable model for annihilation into three non-resonant pions.