Proton-Proton Interactions at 1.5 Bev

Abstract

152 interactions of 1.5-Bev protons have been observed in a hydrogen-filled diffusion cloud chamber. The data indicate an elastic cross section of 20 millibarns, with about 22 millibarns cross section for single pion production and 5 millibarns for double pion production Most single pion production cases are $p+p\ensuremath{\rightarrow}p+n+{\ensuremath{\pi}}^{+}$; no $\mathrm{definite}\mathrm{case}\mathrm{of}\ensuremath{\rightarrow}d+{\ensuremath{\pi}}^{+} or\ensuremath{\rightarrow}p+p+{\ensuremath{\pi}}^{0}$ were observed. The median elastic scattering angle is 24\ifmmode^\circ\else\textdegree\fi{} in the c.m. system. Inelastic events have pions emitted isotropically with low momenta, nucleons emitted near 0\ifmmode^\circ\else\textdegree\fi{} and 180\ifmmode^\circ\else\textdegree\fi{} with high momenta. The average relative energy ($Q$ value) for the $p$, ${\ensuremath{\pi}}^{+}$ pair is 154 Mev.