Generalized parton distributions from hadronic observables: Zero skewness

Abstract

We propose a physically motivated parametrization for the unpolarized generalized parton distributions. At zero value of the skewness variable, $\ensuremath{\zeta}$, the parametrization is constrained by simultaneously fitting the experimental data on both the nucleon elastic form factors and the deep inelastic structure functions. A rich phenomenology can be addressed based on this parametrization. In particular, we track the behavior of the average: (i) interparton distances as a function of the momentum fraction, $X$, (ii) $X$ as a function of the four-momentum transfer, $t$; and (iii) the intrinsic transverse momentum ${k}_{\ensuremath{\perp}}$ as a function of $X$. We discuss the extension of our parametrization to $\ensuremath{\zeta}\ensuremath{\ne}0$ where additional constraints are provided by higher moments of the generalized parton distributions obtained from ab initio lattice QCD calculations.