Forward J/ + J/ and J/ + ^ production with High Energy Factorization

We calculate the cross sections of associated J/ + ^ and J/ + J/ production in pp collisions at s = 13 TeV in the forward kinematic region. The High Energy Factorization (kT-factorization) framework supplemented with the Catani-Ciafaloni-Fiorani-Marchesini evolution of gluon densities in a proton is applied. We demonstrate that latest data on J/ + J/ production and first experimental data on J/ + ^ events taken very recently by the LHCb Collaboration can be described well by the color singlet terms and contributions from the double parton scattering (DPS) with the standard choice for ₄₅₅ parameter. The relative production rate (J/ + ^) / (J/ + J/) is found to be sensitive to the DPS terms as well as to feeddown contributions.