J/ψ photo- and electroproduction, the saturation scale and the gluon structure function

Our approach to low-x deep inelastic scattering based on the l→⊥ factorization of perturbative QCD (the color-dipole picture) yields parameter-free absolute predictions for J/ψ production. The connection of J/ψ production to the low-x saturation scale and to the gluon structure function is clarified.