Deeply Virtual Compton Scattering with CLAS12 at Jefferson Lab

¹ Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France

^* e-mail: ajhobart@jlab.org

Published online: 8 December 2023

Abstract

A key step toward a better understanding of the nucleon structure is the study of Generalized Parton Distributions (GPDs). GPDs are the object of an intense effort of research since they convey an image of the nucleon structure where the longitudinal momentum and the transverse spatial position of the partons inside the nucleon are correlated. Moreover, GPDs give access, via Ji’s sum rule, to the contribution of the orbital angular momentum of the quarks to the nucleon spin, which is important to the understanding of the origins of the nucleon spin. Deeply Virtual Compton scattering (DVCS), the electroproduction of a real photon off the nucleon at the quark level, is the golden process directly interpretable in terms of GPDs of the nucleon. The GPDs are accessed in DVCS mainly through the measurements of single- or double- spin asymmetries. Combining measurements of asymmetries from DVCS experiments on both the neutron and the proton will allow us to perform the flavor separation of the u and d quarks GPDs via linear combinations of proton and neutron GPDs. This paper introduces recent DVCS measurements from the CLAS12 experiment at Jefferson Lab with the upgraded 11 GeV polarized electron beam. Details on the data analysis along with results on Beam Spin Asymmetries are presented.