Interpretation of Proton-Proton Interactions at Cosmotron Energies

In the absence of numerical predictions based on meson field theory, elastic $p-p$ interactions have been compared with a simple optical model and inelastic ones with statistical theories and considerations based on charge independence. Elastic scattering data are fitted satisfactorily by a spherical interaction region with uniform density, radius 0.93×${10}^{-13\mathrm{}}$ cm and absorption coefficient from 4.3 to 2.7×${10}^{13}$ ${\mathrm{cm}}^{-1\mathrm{}}$. Inelastic interactions provide a confirmatory test of charge independence at 0.81 Bev. Pion multiplicities at 1.5 and 2.75 Bev are higher than predicted by the Fermi statistical theory, but the difference is less than that observed for $n-p$ interactions. The multiplicities observed for $p-p$ interactions are lower than those calculated by Kovacs. Distributions of angle and momentum of particles, and correlation angle and $Q$ values for pairs of particles, in general agree with the predictions of statistical theory at 0.81 Bev and disagree at 1.5 Bev. The data that are not consistent with statistical predictions suggest that a $\pi$-nucleon interaction may affect pion production in an important way, but the data are not sufficiently accurate for definite conclusions.