Evaluation of the elastic pp single-flip helicity amplitude at low momentum transfer and high energies.

Abstract

We report on the evaluation of the single-flip helicity amplitude by analyzing proton-proton elastic polarization data in the four-momentum-transfer[minus][ital t] region from 1.5[times]10[sup [minus]3] to 0.6 (GeV/[ital c])[sup 2]. Recent results around 200 GeV/[ital c] in the low [vert bar][ital t][vert bar] range, where the interference of the electromagnetic and hadronic amplitudes is significant, allow a more reliable evaluation of the single-flip hadronic helicity amplitude [phi][sub 5][sup [ital h]]. Within the experimental errors, our analysis indicates a small and negative real part ([minus]1 to [minus]4 %) and a positive imaginary part (8 to 30 %) for the reduced hadronic single-flip helicity amplitude ([ital m]/ [radical][minus][ital t] )[phi][sub 5][sup [ital h]] with respect to the helicity-averaged hadronic nonflip amplitude. To study the stability of these results, we have also considered data at 45--300 GeV/[ital c] in the 0.057--0.6 (GeV/[ital c])[sup 2] momentum transfer range in conjunction with the aforementioned data.