The production of A ( ~ 0 ) hyperons (henceforth denoted A hyperons for short) and K 0 mesons by negative pions on carbon was investigated. The angular and momentum distribu- tions of these particles and the cross sections for their production are determined, and the cross sections of the different channels of the reactions are estimated. The fraction of strange particles produced in the secondary processes is estimated for the first time. The momentum spectrum of the A hyperons (in the pion-nucleon c.m.s.) is compared with the spectrum for rr-p interactions. The experimental data are compared with the results of cascade-model calculations made by the Monte Carlo method.

The c.m.s. momentum and angular distributions of A hyperons and K0 mesons and of pions involved in the production of A and K0 particles are presented. The experimental distributions are compared with those computed by statistical theory and one-meson graphs. The angular and momentum distributions of particles accompanying the production of K°K0 pairs are compared with those of particles created in 1r-p interactions at 7 GeV without strangeparticle production. It is concluded that 1r-p interactions involving the creation of AK0 and K°K0 pairs are more central than the 1r-p interaction with the usual type of multiple pion production. The 1r-p interaction with strange particle production can be separated into two groups which we call central and peripheral interactions.