Observation of the decay $h_{c}\to3(π^{+}π^{-})π^{0}$

Abstract

Based on $(2712.4\pm14.1)\times10^{6}$ $ψ(3686)$ events collected with the BESIII detector, we study the decays $h_{c}\to3(π^{+}π^{-})π^{0}$, $h_{c}\to2(π^{+}π^{-})ω$, $h_{c}\to2(π^{+}π^{-})π^{0}η$, $h_{c}\to2(π^{+}π^{-})η$, and $h_{c}\to p\bar{p}$ via $ψ(3686)\toπ^{0}h_{c}$. The decay channel $h_{c}\to3(π^{+}π^{-})π^{0}$ is observed for the first time, and its branching fraction is determined to be $\left( {9.28\pm 1.14 \pm 0.77} \right) \times {10^{ - 3}}$, where the first uncertainty is statistical and the second is systematic. In addition, first evidence is found for the modes $h_{c} \to 2(π^{+}π^{-})π^{0}η$ and $h_{c}\to2(π^{+}π^{-})ω$ with significances of 4.8$σ$ and 4.7$σ$, and their branching fractions are determined to be $(7.55\pm1.51\pm0.77)\times10^{-3}$ and $\left( {4.00 \pm 0.86 \pm 0.35}\right) \times {10^{ - 3}}$, respectively. No significant signals of $h_c\to 2(π^+π^-)η$ and $h_{c}\to p\bar{p}$ are observed, and the upper limits of the branching fractions of these decays are determined to be $<6.19\times10^{-4}$ and $<4.40\times10^{-5}$ at the 90% confidence level, respectively.

11 pages, 3 figures