Analyzing power measurement ofppelastic scattering in the Coulomb-nuclear interference region with the 200-GeV/cpolarized-proton beam at Fermilab

The analyzing power $A_N$ of proton-proton elastic scattering in the Coulomb-nuclear interference region has been measured using the 200-GeV/c Fermilab polarized proton beam. A theoretically predicted interference between the hadronic non-spin-flip amplitude and the electromagnetic spin-flip amplitude is shown for the first time to be present at high energies in the region of 1.5 × ${10}^{-3\mathrm{}}$ to 5.0 × ${10}^{-2\mathrm{}}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ four-momentum transfer squared, and our results are analyzed in connection with theoretical calculations. In addition, the role of possible contributions of the hadronic spin-flip amplitude is discussed.