Measurement of Deeply Virtual Compton Scattering with a Polarized-Proton Target

Journal Article · Fri Aug 18 00:00:00 EDT 2006 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.97.072002· OSTI ID:20860687

Chen, S; Eugenio, P; Barrow, S; Coltharp, P; Crede, V; Dennis, L; McAleer, S; Ostrovidov, A I; Riccardi, G; Stokes, B E ^[1]; Avakian, H; Burkert, V D; Bosted, P; Brooks, W K; Cords, D; Degtyarenko, P V; Deur, A; Elouadrhiri, L; Guo, L; Gyurjyan, V ^[2]

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1. Florida State University, Tallahassee, Florida 32306 (United States)
2. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

The longitudinal target-spin asymmetry A{sub UL} for the exclusive electroproduction of high-energy photons was measured for the first time in ep(vector sign){yields}e{sup '}p{gamma}. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH{sub 3} target. A significant azimuthal angular dependence was observed, resulting from the interference of the deeply virtual Compton scattering and Bethe-Heitler processes. The amplitude of the sin{phi} moment is 0.252{+-}0.042{sup stat}{+-}0.020{sup sys}. Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H(tilde sign) and H.

• OSTI ID: 20860687
• Journal Information: Physical Review Letters, Vol. 97, Issue 7; Other Information: DOI: 10.1103/PhysRevLett.97.072002; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMMONIA
ASYMMETRY
CEBAF ACCELERATOR
COMPTON EFFECT
ELECTRONS
ELECTROPRODUCTION
GEV RANGE 01-10
INTERFERENCE
PHOTONS
PROTONS
SPECTROMETERS
SPIN
VECTORS