Theory of Single Pion Production in Proton-Proton Collisions

Simple pion production in nucleon-nucleon collisions in the Bev energy region is studied by means of the picture due to Weiszäcker-Williams (peripheral interaction model) and in the ($\frac{3}{2}, \frac{3}{2}$) resonance approximation for the final state pion-nucleon interaction. The excitation curve for the reaction $p+p\to p+n+{\pi }^{+}$, nucleon momentum distributions, and $Q$-value distributions in the center-of-mass system are calculated and compared with the published experimental data as well as with the work of Lindenbaum and Sternheimer. Agreement is reasonable with both, thus indicating that these particular distributions are insensitive to the isobar production mechanism (single pion exchange), though more recent experiments seem to have indicated clearly a preference for the theory developed here.