Beauty meson decays to charmonuim-like states at LHCb

Abstract

The decays $B^{0}_{s} \to J\psi\pi^{+}\pi^{-}K^{+}K^{-}$ are studied using a data set corresponding to an integrated luminosity of 9fb$^{-1}$, collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The decays $B^{0}_{s} \to J\psi K^{*0}\bar{K^{*0}}$ and $B^{0}_{s} \to \chi_{c1}(3872)K^{+}K^{-}$, where the $K^{+}K^{-}$ pair does not originate from a $\phi$ meson, are observed for the first time. Precise measurements of the ratios of branching fractions between intermediate $\chi_{c1}(3872)\phi$, $J/\psi K^{*0}\bar{K^{*0}}$, $\psi(2S) \phi$ and $\chi_{c1}(3872)K^{+}K^{-}$ states are reported. A structure denoted as $X(4740)$, is observed in the $J/\psi \phi$ mass spectrum with a significance in excess of 5.3 standard deviations. In addition, the most precise single measurement of the mass of the $B^{0}_{s}$ meson is performed.