Deeply Virtual Compton Scattering with CLAS12 at Jefferson Lab

Jul 22, 2022, 2:40 PM
Classroom 512 (APCTP)

Classroom 512


Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk 37673, Korea


Adam Hobart (IJCLab CNRS-IN2P3)


A key step toward a better understanding of the nucleon structure is the study of Generalized Parton Distributions (GPDs). GPDs are nowadays 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, 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 performing the flavor separation of relevant quark GPDs via linear combinations of proton and neutron GPDs. This talk will mainly focus on recent DVCS measurements off proton in unpolarised hydrogen target and off neutron (and off proton) in unpolarized deuterium target from the CLAS12 experiment at Jefferson Lab with the upgraded ~11 GeV CEBAF polarized electron beam. Details on the data analysis along with results on Beam Spin Asymmetries are presented. Possible implications from the foreseeable 20+ GeV upgrade of JLab will be shortly discussed.

Primary author

Adam Hobart (IJCLab CNRS-IN2P3)

Presentation materials