3-D imaging the flavor content of the nucleon

The Jefferson Lab Hall A Collaboration, in an experiment led by researchers at Faculté des Sciences de Monastir in Tunisia, Institut de Physique Nucléaire d'Orsay in France and Old Dominion University in the United States, has recently gathered the first experimental observations of deeply virtual Compton scattering (DVCS) in neutrons. Their experiment, whose results were published in Nature Physics, was motivated by generalized parton distributions (GPDs), a recently developed theoretical framework that describes the internal dynamics of the nucleon (proton or neutron) in terms of quarks and gluons. DVCS is the simplest process involving GPDs. It consists of the scattering of an electron off a nucleon and the emission of a high-energy photon while the nucleon remains intact.