High-energy hadron spin-flip amplitude at small momentum transfer and new AN data from RHIC

In the case of elastic high-energy hadron-hadron scattering, the impact of the large-distance contributions on the behaviour of the slopes of the spin-non-flip and of the spin-flip amplitudes is analysed. It is shown that the long tail of the hadronic potential in impact parameter space leads to a value of the slope of the reduced spin-flip amplitude larger than that of the spin-non-flip amplitude. This effect is taken into account in the calculation of the analysing power in proton-nucleus reactions at high energies. It is shown that the preliminary measurement of A _N for p ¹²C obtained by the E950 Collaboration indeed favours a spin-flip amplitude with a large slope. Predictions for A _N at GeV/c are given.Received: 9 January 2004, Revised: 17 March 2004, Published online: 14 September 2004PACS: 13.85.Dz Elastic scattering - 13.85.Lg Total cross sections - 13.85.-t Hadron-induced high- and super-high-energy interactions (energy > 10 GeV)O.V. Selyugin: On leave from the Bogoliubov Laboratory of Theoretical Physics, JINR, 141980, Dubna, Moscow Region, Russia;