Search for ψ(3686)→γηc(η(1405))→γπ+π−π0
Search for ψ(3686)→γηc(η(1405))→γπ+π−π0
Using a sample of $448.1\ifmmode\times\else\texttimes\fi{}{10}^{6}\text{ }\text{ }\ensuremath{\psi}(3686)$ events collected with the BESIII detector, a search for the isospin violating decay ${\ensuremath{\eta}}_{c}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ via $\ensuremath{\psi}(3686)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}$ is presented. No signal is observed, and the upper limit on $\mathcal{B}(\ensuremath{\psi}(3686)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c})\ifmmode\times\else\texttimes\fi{}\mathcal{B}({\ensuremath{\eta}}_{c}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0})$ is determined to be $1.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ at the 90% confidence level. In addition, a search for …