Hadronic transitions of ${\chi }_{cJ}\to {\eta }_c{\pi }^{+}{\pi }^{-}$ ($J=0$, 1, 2) are searched for using a sample of $1.06\times {10}^8$ $\psi (3686)$ events collected with the BESIII detector at the BEPCII storage ring. The ${\eta }_c$ is reconstructed with $K_S^0{K}^{\pm }{\pi }^{\mp }$ and $K^{+}{K}^{-}{\pi }^0$ final states. No signals are observed in any of the three ${\chi }_{cJ}$ states in either ${\eta }_c$ decay mode. At the 90% confidence level, the upper limits are determined to be $\mathcal{B}({\chi }_{c0}\to {\eta }_c{\pi }^{+}{\pi }^{-})<0.07\%$, $\mathcal{B}({\chi }_{c1}\to {\eta }_c{\pi }^{+}{\pi }^{-})<0.32\%$, and $\mathcal{B}({\chi }_{c2}\to {\eta }_c{\pi }^{+}{\pi }^{-})<0.54\%$. The upper limit of $\mathcal{B}({\chi }_{c1}\to {\eta }_c{\pi }^{+}{\pi }^{-})$ is lower than the existing theoretical prediction by almost an order of magnitude. The branching fractions of ${\chi }_{cJ}\to K_S^0{K}^{\pm }{\pi }^{\mp }{\pi }^{+}{\pi }^{-}$, $K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}{\pi }^0$, $\omega K^{+}{K}^{-}$, and $\varphi {\pi }^{+}{\pi }^{-}{\pi }^0$ $J=0$, 1, 2) are measured for the first time.

• Received 23 August 2012

DOI:https://doi.org/10.1103/PhysRevD.87.012002