On duality of Drell-Yan and $J/\psi$ production processes

It is studied the model on $J/\psi$ production allowing to extract parton distribution functions (PDFs) from the combined analysis with both data on Drell-Yan and $J/\psi$ production processes. It is shown that this, so attractive from theoretical point of view, model, can be safely used in the low energy region $E\lesssim100\,$GeV. The significance of gluon contributions to the $J/\psi$ cross-sections is investigated. The obtained results in the high energy region occur to be rather surprising.