Observation of $J/\psi \to \gamma \eta {\pi }^0$

M. Ablikim, M. N. Achasov, X. C. Ai +412

We present the first study of the process $J/\psi \to \gamma \eta {\pi }^0$ using $(223.7\pm 1.4)\times 10^6$ $J/\psi$ events accumulated with the BESIII detector at the BEPCII facility. The b…