Observation of the &lt;em&gt;B&lt;sub&gt;s&lt;/sub&gt;&lt;/em&gt;&lt;sup&gt;0&lt;/sup&gt; → &lt;em&gt;X&lt;/em&gt;(3872)&lt;em&gt;ϕ&lt;/em&gt; decay

Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Bergauer, T.; Dragicevic, M.; Erö, J.; Escalante Del Valle, A.; Frühwirth, R.; Jeitler, M.; Caminada, L.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H.C.; Kotlinski, D.; Langenegger, U.; Rohe, T.; Vetens, W.

doi:10.1103/PhysRevLett.125.152001

Observation of the B_s⁰ → X(3872)ϕ decay

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Dragicevic M, Erö J, Escalante Del Valle A, Frühwirth R, Jeitler M, Caminada L, Erdmann W, Horisberger R, Ingram Q, Kaestli HC, Kotlinski D, Langenegger U, Rohe T, Vetens W, et al.

Citation

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Dragicevic, M., … Vetens, W. (2020). Observation of the B_s⁰ → X(3872)ϕ decay. Physical Review Letters, 125(15), 152001 (18 pp.). https://doi.org/10.1103/PhysRevLett.125.152001

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:34739

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 B_s⁰ → X(3872)ϕ decay is observed. Decays into J/ψπ⁺π^- and K⁺K^- are used to reconstruct, respectively, the X(3872) and ϕ. The ratio of the product of branching fractions B[B_s⁰ → X(3872)ϕ]B[X(3872) → J/ψπ⁺π^-] to the product B[B_s⁰ → ψ(2S)ϕ]B[ψ(2S) → J/ψπ⁺π^-] is measured to be [2.21 ± 0.29(stat) ± 0.17(syst)]%. The ratio B[B_s⁰ → X(3872)ϕ]/B[B⁰ → X(3872)K⁰] is found to be consistent with one, while the ratio B[B_s⁰ → 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 B_s⁰ meson decays compared to B⁺. The reported observation may shed new light on the nature of the X(3872) particle.