On <i>ξ</i>-Process for DVCS-Amplitude

Abstract

In this note, we demonstrate in detail the ξ-process implementation applied to the deeply virtual Compton scattering amplitude to ensure both the QCD and QED gauge invariance. The presented details are also important for the understanding of the contour gauge used in different processes.

Keywords

• <i>SU</i>(3) and <i>U</i>(1) gauge symmetries
• gauge invariance
• DVCS
• contour gauge
• generalized parton distribution