Large angle p+40Ca elastic scattering at 497.5 MeV

Large angle elastic differential cross section and analyzing power data are reported for 497.5 MeV p+40Ca. The characteristic diffraction pattern extends to the largest momentum transfer, 5.3 fm-1. Theoretical models which incorporate either relativistic or nonrelativistic dynamics do not quantitatively describe the data for q>3.5 fm-1. Possible explanations for the discrepancy are suggested. © 1988 The American Physical Society.