Double Charmonia Production at LHCb

In this note next-to-leading order corrections to double charmonium production at LHCb are considered. It is shown that real gluon emission leads to significant change of the cross sections of considered processes. For example, forbidden at leading order production of C-odd state (Xc)J/Ψ is possible at NLO. Distributions over various kinematical variables are analyzed and the question of separating contributions of different mechanisms (direct J/ΨJ/Ψ production, radiative feed-down from (Xc)J/Ψ, double parton scattering) is considered.