Search for $\psi(3686)\to \gamma\eta_c(\eta(1405))\to \gamma \pi^{+}\pi^{-}\pi^{0}$

Abstract

Using a sample of 448.1×106 ψ(3686) events collected with the BESIII detector, a search for the isospin violating decay ηc→π+π−π0 via ψ(3686)→γηc is presented. No signal is observed, and the upper limit on B(ψ(3686)→γηc→γπ+π−π0) is determined to be 1.6×10−6 at the 90% confidence level. In addition, a search for η(1405)→f0(980)π0 in ψ(3686) radiative decays is performed. No signal is observed, and the branching fraction B(ψ(3686)→γη(1405)→γf0(980)π0→γπ+π−π0) is calculated to be less than $ 5.0\times10^{-7}$ at the 90% confidence level.