NLO corrections to timelike, spacelike and double deeply virtual Compton scattering

Understand

We calculate the O(alpha_s) corrections to the timelike, spacelike and double deeply virtual Compton scattering amplitudes in the generalized Bjorken scaling region.

• Special attention is devoted to studies of the difference between the next to leading order timelike and spacelike coefficient functions, which plays for this process a role analogous to the large K factor which was much discussed in the analysis of inclusive Drell Yan cross sections.
• Also in the present studies the timelike nature of the hard scale gives rise to new absorptive part of the amplitude and to the presence of characteristic pi^2 terms, which can potentially lead to sizeable corrections.