Measurement of Deeply Virtual Compton Scattering Beam-Spin Asymmetries

Journal Article · Fri Apr 25 00:00:00 EDT 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.100.162002· OSTI ID:21128071

Girod, F X ^[1]; Niyazov, R A; Kubarovsky, V ^[2]; Avakian, H; Burkert, V D; Elouadrhiri, L; Stepanyan, S; Boiarinov, S; Brooks, W K; Carman, D S; Degtyarenko, P V; Deur, A; Egiyan, H; Guo, L; Gyurjyan, V; Ito, M M; Laget, J M; Mecking, B A; Mestayer, M D; Niczyporuk, B B ^[2]

---

1. CEA-Saclay, Service de Physique Nucleaire, 91191 Gif-sur-Yvette (France)
2. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

The beam-spin asymmetries in the hard exclusive electroproduction of photons on the proton (e-vectorp{yields}ep{gamma}) were measured over a wide kinematic range and with high statistical accuracy. These asymmetries result from the interference of the Bethe-Heitler process and of deeply virtual Compton scattering. Over the whole kinematic range (x{sub B} from 0.11 to 0.58, Q{sup 2} from 1 to 4.8 GeV{sup 2}, -t from 0.09 to 1.8 GeV{sup 2}), the azimuthal dependence of the asymmetries is compatible with expectations from leading-twist dominance, A{approx_equal}asin{phi}/(1+ccos{phi}). This extensive set of data can thus be used to constrain significantly the generalized parton distributions of the nucleon in the valence quark sector.

• OSTI ID: 21128071
• Journal Information: Physical Review Letters, Vol. 100, Issue 16; Other Information: DOI: 10.1103/PhysRevLett.100.162002; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA). CLAS Collaboration; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
COMPTON EFFECT
ELECTROPRODUCTION
INTERFERENCE
PHOTONS
PROTONS
QUARKS
SPIN