Incoherent production of charmonia off nuclei as a good tool for the study of color transparency

Within a light-cone QCD formalism incorporating color transparency, coherence length effects, and gluon shadowing, we study electroproduction of J/Ψ off nuclei. In contrast to light vector meson production when at small and medium energies color transparency and coherence length effects are not easily separated, in charmonium production color transparency effects dominate. We found rather large color transparency effects in the range of Q2≤20 GeV2. They are stronger at low than at high energies and can be easily identified by the planned future experiments. Model calculations explain well the data of the New Muon Collaboration on the Sn/C ratio of nuclear transparencies as a function of the photon energy. We provide predictions for incoherent and coherent charmonium production for future measurements