CMS quarkonium Production at 13 TeV

A wide range of studies of quarkonium production and spectroscopy are performed by the CMS experiment. The quarkonium system is interesting and can be used mainly to probe the underlying Quantum Cromo Dynamics (QCD) processes but also to tune MC generators at new energies, since heavy flavour (HF) states are background to many searches, and can be used to obtain calibration and understanding of the detectors. Events are selected from muon pairs, and the final state includes hadrons and photons. The identification of secondary vertices allows for the separation of prompt (P) and non prompt (NP) production. In the conference talk I presented the many recent results obtained with 13 TeV data at the Large Hadron Collider (LHC) but in this paper I focus on the most recent result: the first observation of resolved χ b1(3P) and χ b2(3P) states and their mass splitting measurement through the decay channel χb (3P) → Υ(3S)γ.