Isobar Model for Meson Production in Proton-Proton Collisions

A model is considered for single- and double-pion production in which the production takes place via an intermediate state wherein either one or both of the initial nucleons is excited to the isobaric state of $J=I=\frac{3}{2}$. The treatment is phenomenological and comparison is made with recent experiments in the 0.5- to 1.5-Bev range. Two striking features of the experiments, the strong preference for the emission of mesons with kinetic energies of 50 to 150 Mev, and the rapid increase in the two-meson processes at bombarding energies above 1 Bev, are exhibited by the calculation.