Measurement of the Branching Fraction of \boldmath{$\psi (2S)\to \gamma {\pi }^0$}

BESIII Collaboration, M. Ablikim, M. N. Achasov +650

Based on $(2712.4\pm 14.1)\times 10^6\psi (2S)$ events, 7.9 fb${}^{-1}$ $\psi (3773)$ data, and 0.8 fb${}^{-1}$ off-resonance data samples collected with the BESIII detector, we measure the b…