Deeply virtual Compton scattering at small x_B and the access to the GPD H

2009/04/30 by Kresimir Kumericki, Dieter Mueller · 2 citations
Physics and Astronomy · #hep-ph #hep-ex

paper · pdf · doi:10.1016/j.nuclphysb.2010.07.015

published as Nucl.Phys.B841:1-58,2010 · LaTeX, 71 page, 15 figures, Sect. 5 improved, matches published version

arxiv created 2010/08/16 · arxiv updated 2015/03/13

Abstract

We give a partonic interpretation for the deeply virtual Compton scattering (DVCS) measurements of the H1 and ZEUS collaborations in the small-x_B region in terms of generalized parton distributions. Thereby we have a closer look at the skewness effect, parameterization of the t-dependence, revealing the chromomagnetic pomeron, and at a model dependent access to the anomalous gravitomagnetic moment of nucleon. We also quantify the reparameterization of generalized parton distributions resulting from the inclusion of radiative corrections up to next-to-next-to-leading order. Beyond the leading order approximation, our findings are compatible with a `holographic' principle that would arise from a (broken) SO(2,1) symmetry. Utilizing our leading-order findings, we also perform a first model dependent dispersion relation fit of HERMES and JLAB DVCS measurements. From that we extract the generalized parton distribution H on its cross-over line and predict the beam charge-spin asymmetry, measurable at COMPASS.

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