A precision measurement of the analyzing power Ay in the elastic pp scattering at 50.04 MeV

The proton-proton interaction has been studied intensively for a long time. At low energies the phase shifts are well determined. However, the precision of the phase shifts for energies around 50 MeV is still not sufficient to distinguish between different model calculations. Therefore, it was suggested a long time ago to measure the analyzing power Ay at roughly 50 MeV with a high precision of the order of a few times 10-4 in order to reduce the uncertainties in the 3PT tensor and the spin-orbit 3PLS p-wave parameters. Such an experiment is described making use of the 50-MeV polarized proton beam from the SIN injector cyclotron. 9 refs.; 2 figs.; 1 table