Beauty meson decays to charmonuim-like states at LHCb

Abstract

The decays $B_s^0\to J\psi {\pi }^{+}{\pi }^{-}{K}^{+}{K}^{-}$ 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 $B_s^0\to J\psi K^{\ast 0}\overline{K^{\ast 0}}$ and $B_s^0\to {\chi }_{c1}(3872)K^{+}{K}^{-}$, where the $K^{+}{K}^{-}$ pair does not originate from a $\varphi$ meson, are observed for the first time. Precise measurements of the ratios of branching fractions between intermediate ${\chi }_{c1}(3872)\varphi$, $J/\psi K^{\ast 0}\overline{K^{\ast 0}}$, $\psi (2S)\varphi$ and ${\chi }_{c1}(3872)K^{+}{K}^{-}$ states are reported. A structure denoted as $X(4740)$, is observed in the $J/\psi \varphi$ mass spectrum with a significance in excess of 5.3 standard deviations. In addition, the most precise single measurement of the mass of the $B_s^0$ meson is performed.

Talk at the 23rd International Conference in Quantum Chromodynamics, Montpellier, France, 27 - 30 Oct 2020

References in corpus (3)

• Observation of a resonance-like structure in the pi^+- psi' mass distribution in exclusive B-->K pi^+- psi' decays
• Excited heavy tetraquarks with hidden charm
• Model-independent observation of exotic contributions to $B^0\to J/\psi K^{+}{\pi }^{-}$ decays