Inelastic Scattering of 220-Mevπ−Mesons in Emulsions

The nuclear interaction of 220-Mev negative $\pi$ mesons has been studied in photographic emulsions. A particular type of inelastic scattering events has been analyzed. Among $1960{\pi }^{-}$ meson interactions, 17 events are observed where the $\pi$ meson transferred a large fraction of its initial energy to a single proton. The incident $\pi$ meson, the scattered $\pi$ meson, and the proton are nearly coplanar in most of these cases. However the three tracks are not exactly coplanar indicating that the meson collision was not with a hydrogen nucleus. The 17 events are interpreted as the interaction of the incident $\pi$ meson with a single proton of the target nucleus.