Study of charmonium production via the decay to pp̄ at $√s = 13 TeV$

Charmonium production cross-section in proton-proton collisions is measured at the centre-of-mass energy √s=13\,TeV using decays to pp̄ final state. The study is performed using a data sample corresponding to an integrated luminosity of 2.2\,fb⁻¹ collected in 2018 with the $LHCb$ detector. The production cross-section of the ηc meson is measured in a rapidity range of $2.0 < y < 4.0$ and in a transverse momentum range of 5.0 < pT < 20.0\,GeV/c, which is extended compared with previous $LHCb$ analyses. The differential cross-section is measured in bins of pT and, for the first time, of y. Upper limits, at 90% and 95% confidence levels, on the ηc(2S) and hc(1P) prompt production cross-sections are determined for the first time.