Implication of the overlap representation for modelling generalized parton distributions

Abstract Based on a field theoretically inspired model of light-cone wave functions, we derive valence-like generalized parton distributions and their double distributions from the wave function overlap in the parton number conserved s -channel. The parton number changing contributions in the t -channel are restored from duality. In our construction constraints of positivity and polynomiality are simultaneously satisfied and it also implies a model dependent relation between generalized parton distributions and transverse momentum dependent parton distribution functions. The model predicts that the t -behavior of resulting hadronic amplitudes depends on the Bjorken variable x Bj . We also propose an improved ansatz for double distributions that embeds this property.