Nuclear shadowing in deep inelastic scattering on nuclei at very small x

Nuclear shadowing corrections to the structure functions of deep inelastic scattering on intermediate-mass nuclei are calculated at very small values of Bjorken x and small values of Q^2 (Q^2<5 Gev^2). The two-component approach developed in previous works of authors for a description of the nucleon structure functions of deep inelastic scattering is used. It is shown that the hard component of the nucleon structure functions that arises, in terms of the colour dipole model, from qq-pairs with a high transverse momentum, is almost not shadowed. It is shown that a change of the slope of the shadowing curve with a decrease of x depends, at small values of x, on the relative contribution of the hard component to the nucleon structure function (this contribution is a function of x and Q^2) and on a size of gluon saturation effects. It is shown that an accounting for saturation effects becomes essential for predictions of shadowing at x<10^-4, depending on a value of Q^2. Results of numerical calculations of nuclear shadowing for several nuclei are compared with available data of the E665 and the NMC collaborations.