Meson production in ${\pi }^{-}p$ and ${\pi }^{+}n$ interactions at 1.7 GeV/c has been studied in two bubble-chamber exposures. Combined results are presented with emphasis on single-pion production (4300 events) which is dominated by the formation of the ${\rho }^0$ meson in peripheral interactions, and on double-pion production (1100 events) which shows strong formation of the $\omega$ meson. These data are compared with the predictions of particle-exchange models, including absorption, and the effects of competing channels are discussed. Evidence for a two-pion decay mode of the $\omega$ is examined quantitatively. Processes with higher meson multiplicities are described.

• Received 6 January 1967

DOI:https://doi.org/10.1103/PhysRev.157.1263