ASSOCIATIVE PRODUCTION OF J/ψ -MESONS AND DIRECT PHOTONS AT THE ENERGY OF THE NICA COLLIDER

The article considers the associated production of J/-mesons and direct photons at the energy of the NICA collider, s =27 GeV, in the Generalized Parton Model in the leading order of perturbation theory of the quantum chromodynamics. Hadronization of a pair of cc-quarks to a J/-meson is described in terms of two approaches: the color singlet model and the color evaporation model. Nonperturbative parameters of the models are fixed from comparison with the available experimental data on inclusive production of J/-mesons obtained at energies from s = 19 up to s = 200 GeV. It is shown that the processes of the associative production of J/ + can be used to study of gluon distribution functions depending on the transverse momentum in a proton.