Unitary constraints on Deeply Virtual Compton Scattering

Abstract

At moderately low momentum transfer (-t up to 1 GeV^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 has 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.

5 pages, 6 figures

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Cited by in corpus (10)

• Deeply Virtual Compton Scattering Beam-Spin Asymmetries
• Sum rules and dualities for generalized parton distributions: is there a holographic principle?
• Exclusive Neutral Pion Electroproduction in the Deeply Virtual Regime
• Exclusive Meson Photo- and Electro-production, a Window on the Structure of Hadronic Matter
• Deeply Virtual Exclusive Processes and Generalized Parton Distributions
• Deeply Virtual Compton Scattering with CLAS
• Discussion on the recent proton-DVCS results of Jefferson Lab
• Hard exclusive scattering at Jlab
• Beam Spin Asymmetries in DVCS with CLAS at 4 .8 GeV
• Parton promenade into the nucleon