Kinematic Issues of GPDs in DVCS

Generalized Parton Distributions (GPDs) in Deeply Virtual Compton Scattering (DVCS) have been widely recognized and used as a useful tool to explore the quark and gluon structure of the target hadrons. However, we recently pointed out treacherous kinematic issues in analyzing DVCS in terms of GPDs. We present our key findings in the simplest possible level of complete amplitude including the lepton current. We also discuss an implication on theoretical frameworks to cover the kinematic region of DVCS experiment with the 12 GeV upgrade at Jefferson Lab.