pp interactions at 10 GeV/c

About 3700 two-prong and 5600 four-prong events of 10-GeV/c $\mathrm{pp}$ interactions in the Saclay 81-cm hydrogen bubble chamber have been measured and analyzed. The reliability of the identification of the different final states has been checked using Monte Carlo-generated events. For the channels accessible to analysis, cross sections and invariant-mass distributions are given. The c.m. angular distributions and the mean values of the transverse momentum for all final-state particles are shown and discussed. Production of ${\ensuremath{\Delta}}^{++}(1236)$ accounts for about 30% of the cross section $\ensuremath{\sigma}(pp\ensuremath{\rightarrow}\mathrm{pn}{\ensuremath{\pi}}^{+})=4.1\ifmmode\pm\else\textpm\fi{}0.4$ mb. About 50% of the cross section $\ensuremath{\sigma}(pp\ensuremath{\rightarrow}\mathrm{pp}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})=2.4\ifmmode\pm\else\textpm\fi{}0.2$ mb can be accounted for by ${\ensuremath{\Delta}}^{++}$ production. Production of nucleon isobars at 1450, 1520, and 1730 MeV and their subsequent decay into $p{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ are investigated. Their cross sections, $t$ dependences, and branching ratios are determined, using a one-pion-exchange model (OPEM) for calculating the background distributions. The production of resonances decaying into $p{\ensuremath{\pi}}^{\ensuremath{-}}$ at 1236, 1500, and 1690 MeV is seen, and cross sections are given. Resonance production in the $\mathrm{pp}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ and $\mathrm{pn}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ reactions is studied using background curves calculated with a model based on simple parametrizations of the c.m. momentum distributions. The production of nucleon isobars accounts for nearly 100% of these reactions. For the reactions $\mathrm{pp}\ensuremath{\rightarrow}\mathrm{pp}\ensuremath{\omega}, \mathrm{pp}\ensuremath{\eta}, \mathrm{and} \mathrm{pp}{f}^{0}$, the cross sections found are 0.16\ifmmode\pm\else\textpm\fi{}0.03, 0.16\ifmmode\pm\else\textpm\fi{}0.07, and 0.10\ifmmode\pm\else\textpm\fi{}0.04 mb, respectively, corrected for unobserved decay modes. It is shown that most of the gross features of the pion-production reactions can be explained by the OPEM with the form factors of Ferrari and Selleri.