Search for $\ensuremath{\psi}(3686)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}(\ensuremath{\eta}(1405))\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$

Search for $ψ (3686) \to γ η_{c} (η (1405)) \to γ π^{+} π^{-} π^{0}$

M. Ablikim et al. (BESIII Collaboration)

Phys. Rev. D 96, 112008 – Published 20 December 2017

Abstract

Using a sample of $448.1 \times 10^{6} ψ (3686)$ events collected with the BESIII detector, a search for the isospin violating decay $η_{c} \to π^{+} π^{-} π^{0}$ via $ψ (3686) \to γ η_{c}$ is presented. No signal is observed, and the upper limit on $B (ψ (3686) \to γ η_{c}) \times B (η_{c} \to π^{+} π^{-} π^{0})$ is determined to be $1.6 \times 10^{- 6}$ at the 90% confidence level. In addition, a search for $η (1405) \to f_{0} (980) π^{0}$ in $ψ (3686)$ radiative decays is performed. No signal is observed, and the branching fraction $B (ψ (3686) \to γ η (1405)) \times B (η (1405) \to f_{0} (980) π^{0}) \times B (f_{0} (980) \to π^{+} π^{-})$ is calculated to be less than $5.0 \times 10^{- 7}$ at the 90% confidence level.