Three-nucleon interactions: Evidence from polarized pd elastic scattering

Advances in precise computation of three-body reaction observables have spu rred new interest in experimental measurements of proton deuteron elastic s cattering, especially with regard to spin effects. Developments in spin-pol arized internal targets for storage rings have permitted measurements of 19 7 MeV polarized protons scattering from vector polarized deuterons. This wo rk presents measurements of the polarization observables A(y), iT(11), and C-y,C-y in proton-deuteron elastic scattering. When compared to calculation s with and without three-nucleon forces, the measurements indicate that thr ee-nucleon forces make a significant contribution to the observables. This work indicates that three-body forces derived from static nuclear propertie s appear to be crucial to the description of dynamical properties.