Data are presented on inclusive and A pro­ duction in and n + collisions with Al and Au nuclei at 250 GeV/c. Results are given on total inclusive cross sections and their A dependence, as well as on distribu­ tions in Feynman-x^, rapidity y and transverse momen­ tum. Ratios of K$ and of A to n~ production are pre­ sented. The data are compared with predictions of the quark-parton model FRITIOF.

Cross-sections are obtained for coherent interac­ tions of 7r+ and K +-mesons with A1 and Au nuclei at 250 GeV/c, leading to three, five and seven charged mesons. The total coherent cross-section is (4.3 ± 0.5)% of the inelastic cross-section for each of the four meson-nucleus interac­ tions. In 85% of the coherent events, the charged meson pro­ duction is accompanied by neutral mesons. Effective mass distributions are presented for coherently produced particles, including charged mesons and photons, carrying total mea­ sured energy of more than 85% of the initial energy. Charged particle and 7 spectra are analysed. No charge asymmetry is observed within the coherently produced cluster.

Cross-sections are obtained for coherent interac­ tions of 7r+ and K +-mesons with A1 and Au nuclei at 250 GeV/c, leading to three, five and seven charged mesons. The total coherent cross-section is (4.3 ± 0.5)% of the inelastic cross-section for each of the four meson-nucleus interac­ tions. In 85% of the coherent events, the charged meson pro­ duction is accompanied by neutral mesons. Effective mass distributions are presented for coherently produced particles, including charged mesons and photons, carrying total mea­ sured energy of more than 85% of the initial energy. Charged particle and 7 spectra are analysed. No charge asymmetry is observed within the coherently produced cluster.