Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering
Abstract
We present the first measurements of the e→p→epγ cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q2 dependence (from 1.5 to 2.3GeV2) 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 Q2. The helicity-independent cross section is also measured at Q2=2.3GeV2. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2006
- DOI:
- 10.1103/PhysRevLett.97.262002
- arXiv:
- arXiv:nucl-ex/0607029
- Bibcode:
- 2006PhRvL..97z2002C
- Keywords:
-
- 13.60.Fz;
- 13.40.Gp;
- 13.60.Hb;
- 14.20.Dh;
- Elastic and Compton scattering;
- Electromagnetic form factors;
- Total and inclusive cross sections;
- Protons and neutrons;
- Nuclear Experiment
- E-Print:
- 5 pages, 4 figures, 2 tables. Text shortened for publication. References added. One figure removed