Unitarity constraints on deeply virtual Compton scattering
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)
At moderately low momentum transfer (-t up to 1 GeV{sup 2}) the coupling to the vector meson production channels gives the dominant contribution to real Compton and deeply virtual Compton scattering (DVCS). Starting from a Regge pole approach that successfully describes vector meson production, the singular part of the corresponding box diagrams (where the intermediate vector meson-baryon pair propagates on-shell) is evaluated without any further assumptions (unitarity). Such a treatment explains not only the unexpectedly large DVCS unpolarized cross section that has been recently measured at Jefferson Laboratory (JLab), but also all the beam spin and charge asymmetries that have been measured at JLab and Hermes, without explicit need of Generalized Parton Distributions (GPD). The issue of the relationship between the two approaches is addressed.
- OSTI ID:
- 21067873
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 76, Issue 5; Other Information: DOI: 10.1103/PhysRevC.76.052201; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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