How many nucleons are required for nuclear pion absorption?

Inclusive proton spectra from π+ and π- interactions with different nuclei at incident pion energy from 100 MeV to 1 GeV are analyzed with the Cascade-Exciton Model of nuclear reactions. The contributions of different pion absorption mechanisms and the relative role of different particle production mechanisms in these reactions are discussed. The results obtained here, as well as our previous analysis of a large variety of experimental data on pion-nucleus reactions in the bombarding energy range of 0-3 GeV confirm the conclusion that the main absorption mechanism is a two-nucleon one. It is shown that data on pion-induced inclusive proton production, intensively discussed in literature, can be satisfactorily described by the 2 N absorption mechanism if the initial- and final-state interactions are taken into account properly. 39 refs., 4 figs