Parton Densities and Dipole Cross-sections at Small X in Large Nuclei

Unintegrated gluon densities in nuclei, dipole-nucleus cross-sections and quark densities are numerically investigated in the high-colour limit, with the scattering on a heavy nucleus exactly described by the sum of fan diagrams of BFKL pomerons. The initial condition for the evolution in rapidity is quickly forgotten, and the gluon density presents a ”supersaturation” pattern, as previous studies indicated. Both dipole-nucleus crosssections and quark densities present the expected saturation features. Identifying the position in transverse momentum l of the maximum of the gluon distribution with the saturation momentum Qs(y, b), at large rapidities all distributions depend only on one variable [l/Qs(y, b)] or [rQs(y, b)].