Energy dependence of forward-rapidity J / ψ and ψ(2 S) production in pp collisions at the LHC

We present results on transverse momentum (p(T)) and rapidity (y) differential production cross sections, mean transverse momentum and mean transverse momentum square of inclusive J/psi and psi(2S) at forward rapidity (2.5 < y < 4) as well as psi(2S)-to-J/psi cross section ratios. These quantities are measured in pp collisions at center of mass energiesv root s = 5.02 and 13 TeV with the ALICE detector. Both charmonium states are reconstructed in the dimuon decay channel, using the muon spectrometer. Acomprehensive comparison to inclusive charmonium cross sections measured at root s = 2.76, 7 and 8 TeV is performed. A comparison to non-relativistic quantum chromodynamics and fixed-order next-to-leading logarithm calculations, which describe prompt and non-prompt charmonium production respectively, is also presented. A good description of the data is obtained over the full p(T) range, provided that both contributions are summed. In particular, it is found that for p(T) > 15 GeV/c the non-prompt contribution reaches up to 50% of the total charmonium yield.