Nonforward parton densities and soft mechanism for form factors and wide-angle Compton scattering in QCD

The authors argue that at moderately large momentum transfer -t ∼< 10 GeV2, hadronic form factors and wide-angle Compton scattering amplitudes are dominated by mechanism corresponding to overlap of soft wave functions. They show that the soft contribution in both cases can be described in terms of the same universal nonforward parton densities (ND's) F(x;t), which are the simplest hybrids of the usual parton densities and hadronic form factors. They propose a simple model for ND's possessing required reduction properties. Their model easily reproduces the observed magnitude and the dipole t-dependence of the proton form factor F1p(t) in the region 1 GeV2 < -t < 10 GeV2. Their results for the wide-angle Compton scattering cross section follow the angular dependence of existing data and are rather close to the data in magnitude