Dual parameterization and Abel transform tomography for twist-3 DVCS

Understand

We derive dual parameterization for the DVCS amplitude to the twist-3 accuracy.

• The relation of the dual parameterization to the Abel transform tomography for amplitudes of hard exclusive processes is elaborated.
• We prove dispersion relations for the twist-3 DVCS amplitude in the Wandzura -- Wilczek approximation and show that the subtraction constant is given by the D-term form factor.
• The same as in the case of twist-2 DVCS amplitude.