Spin correlations, QCD color transparency, and heavy-quark thresholds in proton-proton scattering.

Abstract

The strikingly large spin-spin correlation ${A}_{\mathrm{NN}}$ observed in $\mathrm{pp}$ elastic scattering at ${p}_{\mathrm{lab}}=2.5 \mathrm{and} 11.75$ GeV/c and the unexpected energy dependence of absorptive corrections to quasielastic proton-proton scattering in a nuclear target can be interpreted in terms of two $J=L=S=1$, $B=2$ resonance structures associated with the strange- and charmed-particle production thresholds, interfering with a perturbative QCD background. The results provide support for the "color-transparency" phenomenon predicted in perturbative QCD away from resonances or heavy-quark thresholds.