PION-INDUCED PION-PRODUCTION IN NUCLEI

The process of pion-induced pion production in nuclei has been studied with the A(pi(+),pi(+)pi(-)) and A(pi(+), pi(+)pi(-)p) reactions for four nuclei H-2, C-12, Ca-40, and Pb-208 at, incident pion energy of T pi+ = 283 MeV. The pi(+)pi(-) and pi(+)pi(-)p particles in the final s tate were detected in coincidence with the CHAOS spectrometer at TRIUM F. By looking at kinematic quantities such as missing momentum and mis sing energy, we have been able to draw some model-independent conclusi ons about the dynamics of the pi --> pi pi process in nuclei. which do not vary significantly with target mass. We find that the incident pi on interacts mainly with one surface nucleon via the leading pi N-->pi pi N channel. The pion pair releases no appreciable energy to the res idual nucleus, which remains substantially bound throughout the reacti on. These findings underline the quasifree nature of the pion producti on reaction in nuclei.