Measurement of proton proton elastic scattering in pure initial spin states at 11.75 GeV/c

The elastic cross section for proton proton scattering at 11.75 GeV/c was measured at the Argonne ZGS using a 50% polarized target. In the range p_⊥²=0.6 → 2.2 (GeV/c)² we obtained precise measurements of $\text{d}\text{σ}\text{d}\text{t(ij)}$ for the ? ?, and ? initial spin states perpendicular to the scattering plane. We confirmed that the asymmetry parameter, A, decreases with energy in the diffraction peak, but is approximately energy-independent at large p_⊥². We found that the spin correlation parameter c_nn acquires rather dramatic structure, and at large p_⊥² seems to grow with energy.