Hadron spin-flip amplitude: an analysis of the new AN data from RHIC

Abstract

Through a direct analysis of the scattering amplitude, we show that the preliminary measurement of the analysing power AN obtained by the E950 Collaboration at different energies are mainly sensitive to the spin-flip part of the amplitude in which the proton scatters with the carbon 12 nucleus as a whole. The imaginary part of this amplitude is negative, and the real part positive. We give predictions for pL = 600 GeV/c, which depend mainly on the size of the real part of the amplitude.

6 pages, 4 figures, LaTeX, to appear in the proceedings of the conference ``Spin and Symmetry'', Prague, July 12-19 (2003)