On Deeply Virtual Compton Scattering at next-to-leading order

摘要

Deeply Virtual Compton Scattering in the near forward kinematic region is thegolden access to Generalized Parton Distributions. We studied the O(alphaS)corrections to the scattering amplitude for both spacelike and timelikekinematics relevant respectively to the leptoproduction of a real photon and tothe photoproduction of a lepton pair. It turns out that these corrections arephenomenologically important and that the gluonic contributions are by no meansnegligible, even in the moderate energy range of JLab12 and of the COMPASS-IIexperiment at CERN.