ASYMMETRIES IN 100 MEV PI(+) PI(-)-HE-3-] ELASTIC-SCATTERING/

We have measured cross sections and analyzing powers for pi+ and pi- e lastic scattering from a polarized He-3 target at T(pi) = 100 MeV. Mea surements have been made over an angular range of 60-degrees to 110-de grees which extends over the region of the cross section minimum where spin effects in pi-nucleus scattering are predicted to be largest. Th is is evident from the large value of A(y) observed in pi+ scattering from He-3 near theta(lab = 80-degrees). The A(y) data for both pi+ and pi- scattering are qualitatively reproduced by a schematic PWIA model ; however, agreement with the data is significantly improved when a fu ll nonlocal DWIA reaction model employing realistic three-body wave fu nctions is used. The asymmetry in pi--He-3 scattering resembles the as ymmetry for pi- scattering from a free neutron near the cross section minimum and is about half that for pi+ scattering.