Modeling nucleon generalized parton distributions.

We discuss building models for nucleon generalized parton distributions H and E that are based on the formalism of double distributions (DDs). We found that the usual "DD + D-term" construction should be amended by an extra term, ξE+¹ (x, &#958) built from the α/β moment of the DD e(β, β) that generates generalized parton distribution E(x, ξ). Unlike the D term, this function has support in the whole -- 1 = x = 1 region, and in general does not vanish at the border points │x│ =ξ [ABSTRACT FROM AUTHOR]