Eur. Phys. J. C (2009) 63: 407-421
https://doi.org/10.1140/epjc/s10052-009-1073-4

Regular Article - Theoretical Physics

Generalized parton distributions from hadronic observables: non-zero skewness

¹ University of Virginia, 382 McCormick Road, Charlottesville, VA, 22904, USA
² Ecole Polytechnique, CPHT, 91128, Palaiseau Cedex, France

^* e-mail: sl4y@virginia.edu

Received: 2 October 2008
Revised: 14 March 2009
Published online: 25 August 2009

Abstract

We propose a physically motivated parameterization for the unpolarized generalized parton distributions, H and E, valid at both zero and non-zero values of the skewness variable, ζ. Our approach follows a previous detailed study of the ζ=0 case where H and E were determined using constraints from simultaneous fits of the experimental data on both the nucleon elastic form factors and the deep inelastic structure functions in the non-singlet sector. Additional constraints at ζ≠0 are provided by lattice calculations of the higher moments of generalized parton distributions. We illustrate a method for extracting generalized parton distributions from lattice moments based on a reconstruction using sets of orthogonal polynomials. The inclusion in our fit of data on Deeply Virtual Compton Scattering is also discussed. Our method provides a step towards an extraction of generalized distributions based on a global fit of the available data within the given set of constraints.