ASYMMETRIES IN ELASTIC-SCATTERING OF 100 MEV PI+ FROM A POLARIZED HE-3 TARGET

We report the observation of a large asymmetry in the elastic scattering of 100 MeV pi+ from a polarized He-3 target. Measurements have been made at laboratory angles of 60-degrees, 80-degrees, and 100-degrees, with the largest value A(y) = 0.89 +/- 0.12 occurring at 80-degrees, near a cross-section minimum. This asymmetry is the largest observed to date in pion scattering from a spin-1/2 nucleus. The A(y) data are qualitatively reproduced by a schematic model; however, agreement with the data is significantly improved when realistic three-body Faddeev wave functions and a full nonlocal distorted-wave impulse approximation reaction model are used.