Observation of $X(3872)$ in $B\to X(3872)K\pi$ decays

Abstract

We report the first observation of $B^0\to X(3872)(K^{+}{\pi }^{-})$ and evidence for $B^{+}\to X(3872)(K^0{\pi }^{+})$. We measure the product of branching fractions for the former to be ${\cal B}(B^0 \to X(3872) (K^+ π^-)) \times {\cal B}(X(3872) \to J/ψπ^+ π^-) = (7.9 \pm 1.3(\mbox{stat.})\pm 0.4(\mbox{syst.})) \times 10^{-6}$ and find that $B^0\to X(3872)K^{\ast }(892{)}^0$ does not dominate the $B^0\to X(3872)K^{+}{\pi }^{-}$ decay mode. We also measure ${\cal B}(B^+ \to X(3872) (K^0 π^+)) \times {\cal B}(X(3872) \to J/ψπ^+ π^-) = (10.6 \pm 3.0(\mbox{stat.}) \pm 0.9(\mbox{syst.})) \times 10^{-6}$. This study is based on the full data sample of 711~fb${}^{-1}$ ($772\times 10^{6}B\bar{B}$ pairs) collected at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB collider.

7 pages, 3 figures

References in corpus (2)

• Big-Bang Nucleosynthesis
• Evidence for the decay $X(3872)\to \psi (2S)\gamma$

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• Production of $X(3872)$ Accompanied by a Pion in $B$ Meson Decay
• Triangle singularity appearing as an $X(3872)$-like peak in $B\to (J/\psi {\pi }^{+}{\pi }^{-})K\pi$
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• Search for $XYZ$ states in ${\Lambda }_b$ decays at the LHCb
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