Near-threshold pion production by protons on nuclei

The p + p → d + π⁺ process is considered in detail along with the p + N → N + N + π process. Such consideration makes it possible to show the difference in the production cross sections for π⁺ and π^? mesons on nuclei. In this case, experimental data can be reproduced both above the pion production threshold at a proton energy of 350 MeV and under the threshold at a proton energy of 180 MeV.