Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering

Journal Article · Sun Dec 31 00:00:00 EST 2006 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.97.262002· OSTI ID:20861542

Camacho, C Munoz; Beaumel, M; Garcon, M; Guichon, P A. M.; Sabatie, F ^[1]; Camsonne, A; Ferdi, C; Brossard, M; Fieschi, J -M; Laveissiere, G; Michel, B ^[2]; Mazouz, M; Guillon, B; Real, J -S; Voutier, E ^[3]; Gavalian, G; Amarian, M; Hayes, D; Hyde-Wright, C E; Ibrahim, H ^[4]

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1. CEA Saclay, DAPNIA/SPhN, F-91191 Gif-sur-Yvette (France)
2. Universite Blaise Pascal/CNRS-IN2P3, F-63177 Aubiere (France)
3. Laboratoire de Physique Subatomique et de Cosmologie, 38026 Grenoble (France)
4. Old Dominion University, Norfolk, Virginia 23508 (United States)

We present the first measurements of the e(vector sign)p{yields}ep{gamma} cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q{sup 2} dependence (from 1.5 to 2.3 GeV{sup 2}) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q{sup 2}. The helicity-independent cross section is also measured at Q{sup 2}=2.3 GeV{sup 2}. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.

• OSTI ID: 20861542
• Journal Information: Physical Review Letters, Vol. 97, Issue 26; Other Information: DOI: 10.1103/PhysRevLett.97.262002; (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

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
APPROXIMATIONS
COMPTON EFFECT
CROSS SECTIONS
DISTRIBUTION
HELICITY
QUARKS