Spectator-Tagged Deeply Virtual Compton Scattering on Light Nuclei

Abstract

The three-dimensional picture of quarks and gluons in the proton is set to be revealed through Deeply virtual Compton scattering while a critically important puzzle in the one-dimensional picture remains, namely, the origins of the EMC effect. Incoherent nuclear DVCS, i.e. DVCS on a nucleon inside a nucleus, can reveal the 3D partonic structure of the bound nucleon and shed a new light on the EMC effect. However, the Fermi motion of the struck nucleon, off-shell effects and final-state interactions (FSIs) complicate this parton level interpretation. We propose here a measurement of incoherent DVCS with a tagging of the recoiling spectator system (nucleus A-1) to systematically control nuclear effects. Through spectator-tagged DVCS, a fully detected final state presents a unique opportunity to systematically study these nuclear effects and cleanly observe possible modification of the nucleon's quark distributions. We propose to measure the DVCS beam-spin asymmetries (BSAs) on ${}^4$He and deuterium targets. The reaction ${}^4$He$(e,e^{\prime }\gamma p{}^3$H$)$ with a fully detected final state has the rare ability to simultaneously quantify FSIs, measure initial nucleon momentum, and provide a sensitive probe to other nuclear effects at the parton level. The DVCS BSA on a (quasi-free) neutron will be measured by tagging a spectator proton with a deuteron target. Similarly, a bound neutron measurement detects a spectator ${}^3$He off a ${}^4$He target. These two observables will allow for a self-contained measurement of the neutron off-forward EMC Effect.

References in corpus (18)

• Nonforward Parton Distributions
• Theory of deeply virtual Compton scattering on the nucleon
• Generalized Parton Distributions in the valence region from Deeply Virtual Compton Scattering
• Measurement of deeply virtual Compton scattering at HERA
• Deeply Virtual Compton Scattering Beam-Spin Asymmetries
• Nucleon and nucleon-pair momentum distributions in A <= 12 nuclei
• Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering
• Polarization Transfer in the 4He(e,e'p)3H Reaction at Q^2 = 0.8 and 1.3 (GeV/c)^2
• Spin-dependent structure functions in nuclear matter and the polarized EMC effect
• Leading twist asymmetries in deeply virtual Compton scattering
• Deep Electroproduction of Photons and Mesons on the Deuteron
• Geometrical approach to the proton spin decomposition
• Is the Coulomb sum rule violated in nuclei?
• DVCS on spinless nuclear targets in impulse approximation
• The Quasielastic 3He(e,e'p)d Reaction at Q^2 = 1.5 GeV^2 for Recoil Momenta up to 1 GeV/c
• Nuclear Medium Modifications of Hadrons from Generalized Parton Distributions
• A precise extraction of the induced polarization in the 4He(e,e'p)3H reaction
• Connection between In Medium Nucleon Form Factors and Deep Inelastic Structure Functions

Cited by in corpus (6)

• Coherent deeply virtual Compton scattering off ${}^4$He
• Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab
• Measurement of deeply virtual Compton scattering off Helium-4 with CLAS at Jefferson Lab
• Incoherent deeply virtual Compton scattering off ${}^4$He
• Deeply virtual Compton scattering off Helium nuclei with positron beams
• The neutron and proton mass radii from the vector meson photoproduction data on the deuterium target