Determination of analyzing powers for 189 MeV proton elastic scattering onC12

Abstract
The analyzing power Ay for proton elastic scattering on C12 has been precisely and absolutely determined at three scattering angles (θlab=16.3°, 17.3°, and 18.3°) at an incident proton energy of 188.9 MeV. The technique employed requires statistically high quality polarization transfer measurements, combined with the constraints imposed on polarization observables for reactions with the spin structure 1/2+0→1/2+0. These results represent some of the most accurately known spin observables at intermediate energies and serve as calibration points for secondary standards.