Characteristics of Multipion Production at 3.9 and 11.9 GeV/c

A quasi-two-body model based on one-particle exchange and diffraction dissociation has been fitted to data from ${\pi }^{-}p$ interactions at 3.9 and 11.9 GeV/c in which a nucleon and 3-6 pions are present in the final state. It is used to estimate partial cross sections for the contributing interaction mechanisms and the dominant resonances which are produced at these energies. The energy dependence of the cross sections is examined and found to be consistent with expected behavior, and reactions are compared and found to agree with simple factorization.