The Production of Positive Pions by 341-Mev Protons on Protons

The production of positive pions by protons on protons has been studied at 0°, 35°, and 58° to the beam of 341-Mev protons produced by the Berkeley synchrocyclotron. In the collision of two protons, two reactions are possible which lead to a ${\pi }^{+}$ meson: (1) $P+P\to {\pi }^{+}+D$ and (2) $P+P\to {\pi }^{+}+N+P$. The experimental results at 0° show an energy spectrum from 0 to 70 Mev which is fairly flat except for a large peak at the high-energy end. The flat portion of the spectrum can only be due to reaction (2). A comparison of the shape of the peak with the results of the phenomenological theory of Brueckner and Watson shows that the peak is due solely to reaction (1).