COMPARISON OF ANALYZING POWER PREDICTIONS FOR PP SCATTERING IN THE COULOMB-NUCLEAR INTERFERENCE REGION AT 185.4 MEV

Recent measurements of the analyzing power A(y) for elastic proton-proton scattering are compared to predictions of phase-shift analyses and potential models. One measurement is an absolute determination of A(y) at a beam energy of 183.1 MeV. The second measurement is a precise determination of the angular distribution A(y)(theta) over the angular range theta(c.m.) = 5.45-degrees-21.36-degrees at a beam energy of 185.4 MeV. At these small angles the interference between the Coulomb and nuclear amplitudes dominates A(y)(theta). Potential model calculations without the electromagnetic spin-orbit force fail to reproduce the data. Phase-shift analyses, all of which include some form of the electromagnetic spin-orbit force, tend to have a better overall agreement with the data than the potential models.