Deeply Virtual Compton Scattering at 6.5 GeV and 7.5 GeV Polarized Electron Beam with CLAS12

Deeply Virtual Compton Scattering (DVCS) is the cleanest channel providing access to the 3D imaging of the nucleon structure described by Generalized Parton Distributions (GPDs) which correlates the 1D longitudinal momentum fraction of the nucleon’s constituent to its 2D transverse position. In the DVCS reaction, the interaction of the virtual photon from scattered electron and a quark inside the nucleon results in the nucleon’s emission of a high-energy real photon. Detection of DVCS events also means detection of Bethe-Heitler (BH) events, which have the same final-state particles but with the photons emitted by scattered electrons. By conducting DVCS experiments at different beam energies, separation of DVCS and DVCS-BH interference amplitudes can be performed allowing the extraction of GPD H in some kinematics, and eventually the gravitational d₁(t) form factor, which provides access to the mechanical properties of the nucleon.

High luminosity and high polarization of Jefferson Lab’s electron beam together with the large-acceptance CLAS12 detector system in Hall B at Jefferson Lab provide the ideal setup for multi-energy DVCS experiments with efficient particle detection in broad kinematic ranges.

DVCS data were collected with CLAS12 in 2018 at 6.5 GeV, 7.5 GeV, and 10.6 GeV electron beam energies on liquid hydrogen target. We will present preliminary results of DVCS measurements at 6.5 GeV and 7.5 GeV beam energies, focusing on the Beam-Spin Asymmetry, which is particularly sensitive to the H GPD and is an essential ingredient in extracting the d₁(t) form factor.