Measurement of Analyzing Power for Proton-Carbon Elastic Scattering in   the Coulomb-Nuclear Interference Region with a 22-GeV/c Polarized Proton Beam
  The analyzing power for proton-carbon elastic scattering in the coulomb-nuclear interference region of momentum transfer, $9.0\times10^{-3}<-t<4.1\times10^{-2}$ (GeV/$c)^{2}$, was measured with a 21.7 GeV/$c$ polarized proton beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory. The ratio of hadronic spin-flip to non-flip amplitude, $r_5$, was obtained from the analyzing power to be $\text{Re} r_5=0.088\pm 0.058$ and $\text{Im} r_5=-0.161\pm 0.226$. 
J. Tojo, I. Alekseev, M. Bai, B. Bassalleck, G. Bunce, A. Deshpande,   J. Doskow, S. Eilerts, D.E. Fields, Y. Goto, H. Huang...