Extraction of Observables from Deeply Virtual Electron Proton Scattering Experiments

Imaging the 3D partonic structure of the nucleon is a fundamental goal of every major nuclear experimental program, including the EIC. Ji first proposed Deeply Virtual Compton Scattering (DVCS) as a probe for understanding the spatial distribution of the partons by fourier transform of the exchanged momentum transfer between the initial and final proton. The extraction of observables from Deeply Virtual Exclusive Reactions in a clear and concise formalism, such that the various twist components and angular dependencies can be untangled, is key. We present a completely covariant description of the DVCS process. In our helicity formalism, we can separate kinematic subleading terms from dynamic twist, given by the Q² suppression and azimuthal angle ɸ. Since the higher twist terms are characterized by their dependence on ɸ, it is important to understand the angular contribution arising from the kinematics and separate it from the characteristic angular dependence of the higher twist terms. The extension to other Deeply Virtual Exclusive Reactions, such as TCS, is in progress. From our formalism, one can extract observables important in understanding the physical properties of the proton such as the angular momentum of the quarks and gluons inside the proton.