The energy dependence of the saturation momentum from RG improved BFKL evolution

We study the energy dependence of the saturation momentum in the context of the collinearly improved Leading and Next to Leading BFKL evolution, and in the presence of saturation boundaries. We find that the logarithmic derivative of the saturation momentum is varying very slowly with Bjorken-x, and its value is in agreement with the Golec-Biernat and Wijsthoff model in the relevant x region. The scaling form of the amplitude for dipole dipole or dipole-hadron scattering in the perturbative side of the boundary is given. (C) 2002 Elsevier Science B.V. All rights reserved.