Inelastic Scattering of 500-Mev Negative Pions in Emulsion Nuclei

Inelastic scattering of 500-Mev negative pions has been investigated in 1700 meson-induced events in emulsion nuclei. Large energy losses and strong angular relationships of the emitted mesons have been observed, similar to those in experiments with lower energy mesons. The possible causes for this behavior are discussed. In 1-3 percent of the events, production of charged mesons has been found. The cross section for meson production on free nucleons is estimated to be between 3.5 and 10 mb, considering the possible absorption of one or both mesons. The angular and energy distributions of mesons and recoiling nucleons in events with meson production are discussed. Six events of ${\pi }^0$ production on free protons (or edge nucleons) have been found. The results are compared with observations on meson scattering and meson production in cosmic-ray experiments.