Investigation of exotic charmonium states in the LHCb experiment

The most recent results of investigations into exotic charmonium states in the LHCb experiment are presented. The quantum numbers of the X(3872) state were measured, a piece of evidence for the decay X(3872)→ ψ(2S)γ was obtained, and the existence of the Z(4430)$^{-}$ state was confirmed. The analyses that led to these results were based on data accumulated by the LHCb detector in proton–proton collisions at the c.m. energies of 7 and 8 TeV. The data sample used corresponded to integrated luminosities between 1 and 3 fb$^{-1}$.