Large-momentum-transfer Compton scattering

We have used perturbative QCD to calculate the complete set of helicity amplitudes for the real and virtual Compton-scattering reactions ${\gamma }^{\left(\mathrm{*}\right)}$p→γp, using a variety of wave functions. A particularly interesting feature of these results is the existence of nontrivial phases in the amplitudes, and a great deal of structure in the amplitudes as a function of the virtuality of the initial photon. Results for ${\mathit{s}}^6$ dσ/dt(γp→γp) are compared to existing data.