Observation of the B${}_{\mathrm{s}}^0$ $\to$ X(3872)$\varphi$ decay

Abstract

Using a data sample of proton-proton collisions at $\sqrt{s}=$ 13 TeV, corresponding to an integrated luminosity of 140 fb${}^{-1}$ collected by the CMS experiment in 2016-2018, the B${}_{\mathrm{s}}^0$ $\to$ X(3872)$\varphi$ decay is observed. Decays into J/$\psi {\pi }^{+}{\pi }^{-}$ and K${}^{+}$K${}^{-}$ are used to reconstruct, respectively, the X(3872) and $\varphi$. The ratio of the product of branching fractions $\mathcal{B}($B${}_{\mathrm{s}}^0$ $\to$ X(3872)$\varphi )\mathcal{B}($X(3872) $\to$ J$/\psi {\pi }^{+}{\pi }^{-})$ to the product $\mathcal{B}($B${}_{\mathrm{s}}^0$ $\to$ $\psi$(2S)$\varphi )\mathcal{B}(\psi$(2S) $\to$ J/$\psi {\pi }^{+}{\pi }^{-})$ is measured to be (2.21 $\pm$ 0.29 (stat) $\pm$ 0.17 (syst))%. The ratio $\mathcal{B}($B${}_{\mathrm{s}}^0$ $\to$ X(3872)$\varphi )/\mathcal{B}($B${}^0$ $\to$ X(3872)K${}^0)$ is found to be consistent with one, while the ratio $\mathcal{B}($B${}_{\mathrm{s}}^0$ $\to$ X(3872)$\varphi )/\mathcal{B}($B${}^{+}$ $\to$ X(3872)K${}^{+})$ is two times smaller. This suggests a difference in the production dynamics of the X(3872) in B${}^0$ and B${}_{\mathrm{s}}^0$ meson decays compared to B${}^{+}$. The reported observation may shed new light on the nature of the X(3872) particle.

Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/BPH-17-005 (CMS Public Pages)

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Cited by in corpus (4)

• Observation of multiplicity-dependent prompt ${\chi }_{c1}(3872)$ and $\psi (2S)$ production in $pp$ collisions
• A Phenomenological analysis on isospin-violating decay of $X(3872)$
• Study of $e^{+}{e}^{-}\to \omega X(3872)$ and $\gamma X(3872)$ from 4.66 to 4.95 GeV
• Search for the $e^{+}{e}^{-}\to \varphi {\chi }_{c1}(3872)$ process at BESIII