Article révisé par les pairs
Résumé : We present results on π+-p interactions at 500 MeV from an experiment performed with the Saclay 35 cm hydrogen bubble chamber. A total of 1840 events have been observed. The branching ratio for elastic events is equal to 0.883±0.008. Eight events are unambiguously attributed to the reaction π+p→π+pγ. Cross sections for the various reactions are given. The elastic angular distribution has been determined up to cos θ = +0.975 and shows evidence for S, P, D waves in good agreement with the results obtained in other experiments. For the one-pion production reactions, the ration of π0 production to π0 production is found equal to 4.1±0.8. This result and the corresponding distributions for momentum and angle of the secondaries are compared with the predictions of the isobaric models. © 1965.