Measurements of the branching fractions of the $P$-wave charmonium spin-singlet state $h_c{(}^1{P}_1)\to h^{+}{h}^{-}{\pi }^0/\eta$

Abstract

Based on $(2712.4\pm 14.3)\times 10^6$ $\psi (3686)$ events, we investigate four hadronic decay modes of the $P$-wave charmonium spin-singlet state $h_c{(}^1{P}_1)\to h^{+}{h}^{-}{\pi }^0/\eta$ ($h=\pi$ or $K$) via the process $\psi (3686)\to {\pi }^0{h}_c$ at BESIII. The $h_c\to {\pi }^{+}{\pi }^{-}{\pi }^0$ decay is observed with a significance of 9.6$\sigma$ after taking into account systematic uncertainties. Evidences for $h_c\to K^{+}{K}^{-}{\pi }^0$ and $h_c\to K^{+}{K}^{-}\eta$ are found with significances of $3.5\sigma$ and $3.3\sigma$, respectively, after considering the systematic uncertainties. The branching fractions of these decays are measured to be $\mathcal{B}(h_c\to {\pi }^{+}{\pi }^{-}{\pi }^0)=(1.36\pm 0.16\pm 0.14)\times 10^{-3}$, $\mathcal{B}(h_c\to K^{+}{K}^{-}{\pi }^0)=(3.26\pm 0.84\pm 0.36)\times 10^{-4}$, and $\mathcal{B}(h_c\to K^{+}{K}^{-}\eta )=(3.13\pm 1.08\pm 0.38)\times 10^{-4}$, where the first uncertainties are statistical and the second are systematic. No significant signal of $h_c\to {\pi }^{+}{\pi }^{-}\eta$ is found, and the upper limit of its decay branching fraction is determined to be $\mathcal{B}(h_c\to {\pi }^{+}{\pi }^{-}\eta )<4.0\times 10^{-4}$ at 90% confidence level.

9 pages, 7 figures

References in corpus (6)

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• Cross section measurements of $e^{+}{e}^{-}\to \omega {\chi }_{c0}$ from $\sqrt{s}=$4.178 to 4.278 GeV
• Determination of the number of $\psi (3686)$ events taken at BESIII
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• Search for New Hadronic Decays of $h_c$ and Observation of $h_c\to K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}{\pi }^0$
• Observation of the decay $h_c\to 3({\pi }^{+}{\pi }^{-}){\pi }^0$