Measurement of p/sub arrow-up/+p/sub arrow-up/. -->. p+p with a 16. 5-GeV/c polarized proton beam

Using the new Brookhaven Alternating Gradient Synchrotron polarized proton beam and our polarized proton target, we measured the spin-spin correlation parameter A/sub n/n in 16.5-GeV/c proton-proton elastic scattering. We found an A/sub n/n of (6.1 +- 3.0)% at P/sub perpendicular/ /sup 2/ = 2.2 (GeV/c)/sup 2/. We also measured the analyzing power A in two independent ways, providing a good test of possible experimental errors. Comparing our new data with 12-GeV Argonne Zero Gradient Synchrotron data shows no evidence for strong energy dependence in A/sub n/n in this medium-P/sub perpendicular/ /sup 2/ region.