Asymmetries in elastic scattering of 100 MeVπ+from a polarizedHe3target

1991

We report the observation of a large asymmetry in the elastic scattering of 100 MeV {pi}{sup +} from a polarized {sup 3}He target. Measurements have been made at laboratory angles of 60{degree}, 80{degree}, and 100{degree}, with the largest value {ital A}{sub {ital y}}=0.89{plus minus}0.12 occurring at 80{degree}, near a cross-section minimum. This asymmetry is the largest observed to date in pion scattering from a spin-1/2 nucleus. The {ital A}{sub {ital 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…