MEASUREMENTS OF QUASI-ELASTIC PION SINGLE CHARGE-EXCHANGE ON HE-3 AT T-PI=245 MEV

Differential cross sections from He-3(pi(+/-), pi(0)) and He-3(pi(+/-) , pi(0)p) measurements are presented. The pi(0) energy spectra from He -3(pi(+/-), pi(0)) and He-3(pi(+), pi(0)p) are characteristic of quasi -free reactions. The proton angular distributions from He-3(pi(+), pi( 0)p) also show evidence of a quasi-free mechanism. Indications of mult i-nucleon processes are presented in the He-3(pi(-), pi(0)p) data. At least two nucleons must be involved. Comparisons between coincidence a nd single-arm measurements from this work and previous measurements of charged pion scattering on He-3 provide evidence of an enhanced multi ple scattering contribution to the charge exchange channel.