One-loop corrections and all order factorization in deeply virtual Compton scattering

Abstract

We calculate the one-loop corrections to a general off-forward deeply virtual Compton process at leading twist for both parton helicity-dependent and independent cases. We show that the infrared divergences can be factorized entirely into off-forward parton distributions, even when one of the two photons is on shell. We argue that this property persists to all orders in perturbation theory. We obtain the next-to-leading order Wilson coefficients for the general leading-twist expansion of the product of two electromagnetic currents in the $\overline{\mathrm{MS}}$ scheme.