Nuclear structure functions and heavy flavour leptoproduction off the nucleus at small x in perturbative QCD

Nuclear structure functions and cross-sections for heavy flavour production in lepton-nucleus collisions are investigated in the low x region accessible now or in the near future. The scattering on a heavy nucleus is described by the sum of fan diagrams of BFKL pomerons, which is exact in the high-colour limit. The initial condition for the evolution at x = 0.01 is taken from a saturation model, which reproduces the experimental data on the proton. The A dependence of the structure functions is well described by a power factor A(alpha), with alpha reaching values as low as 1/2 at extremely low x. The total cross-sections for heavy flavour production reach values of the order of mb, and the corresponding transverse momentum distributions are sizable up to transverse momenta larger than the initial large scale (Q(2) + 4m(f)(2))(1/2).