Observation of the B s 0 → X ( 3872 ) ϕ Decay

© 2020 CERN. Using a data sample of proton-proton collisions at s=13 TeV, corresponding to an integrated luminosity of 140 fb-1 collected by the CMS experiment in 2016-2018, the Bs0→X(3872)φ decay is observed. Decays into J/ψ+π- and K+K- are used to reconstruct, respectively, the X(3872) and φ. The...

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Bibliographic Details
Main Author: The CMS Collaboration
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: American Physical Society (APS) 2021
Online Access:https://hdl.handle.net/1721.1/133574
Description
Summary:© 2020 CERN. Using a data sample of proton-proton collisions at s=13 TeV, corresponding to an integrated luminosity of 140 fb-1 collected by the CMS experiment in 2016-2018, the Bs0→X(3872)φ decay is observed. Decays into J/ψ+π- and K+K- are used to reconstruct, respectively, the X(3872) and φ. The ratio of the product of branching fractions B[Bs0→X(3872)φ]B[X(3872)→J/ψ+π-] to the product B[Bs0→(2S)φ]B[ψ(2S)→J/ψ+π-] is measured to be [2.21±0.29(stat)±0.17(syst)]%. The ratio B[Bs0→X(3872)φ]/B[B0→X(3872)K0] is found to be consistent with one, while the ratio B[Bs0→X(3872)φ]/B[B+→X(3872)K+] is two times smaller. This suggests a difference in the production dynamics of the X(3872) in B0 and Bs0 meson decays compared to B+. The reported observation may shed new light on the nature of the X(3872) particle.