The spin correlation parameter A00NN for 497.5 MeV proton + proton elastic scattering was determined over the center-of-momentum scattering angle region 23.1°64.9°. The new A00NN extend to more forward angles than existing A00NN and have significantly smaller statistical errors (0.010.04). The A00NN are qualitatively described by recent phase shift analyses, but a quantitative shape and normalization discrepancy remains in the forward angle region. These new data provide important constraints for nucleon-nucleon spin-dependent amplitudes at forward angles which are used in theoretical models of nucleon-nucleus scattering.
ASJC Scopus subject areas
- Nuclear and High Energy Physics