Proton-proton near-forward hard elastic scattering

We calculate the leading twist contribution to near-forward proton-proton (and proton-anti-proton) elastic scattering with large momentum transfer, in the multiple scattering (Landshoff) mechanism. The near-forward amplitude in this perturbative approach is dominated by singlet exchange for all three valence quark-quark scatterings. We assume the existence of a hard singlet quark-quark amplitude, which we estimate to be O(α_s²/t). For a three-quark state whose transverse size is less than 1/Λ_QCD, Sudakov resummation accounts for both approximate dσ^pp/dt∼t^-8 at moderate t, and dσ^pp/dt∼t^-10 at larger t. The transition from approximate t^-8 to t^-10 behavior is strongly correlated with the transverse size of the valence three-quark state in the proton.