Gluon saturation effects on the color singlet production in high energy dA and AA collisions

We derive the formulae for the cross section of J / psi production in high energy pA and AA collisions taking into account the gluon saturation/color glass condensate effects. We then perform the numerical calculations of the corresponding nuclear modification factors and find a good agreement between our calculations and the experimental data on J / psi production in pA collisions. We also observe that cold nuclear modification effects alone cannot describe the data on J / psi production in AA collisions. Additional final state suppression (at RHIC) and enhancement (at LHC) mechanisms are required to explain the experimental observations.