Observation of K+→π+π0π0γ decay

Abstract

The $K^{+}\to {\pi }^{+}{\pi }^0{\pi }^0\gamma$ decay is observed by the OKA collaboration. About 60 events of the decay observed with signal:noise $\approx 1$. The branching ratio obtained by normalization to $K^{+}\to {\pi }^{+}{\pi }^0{\pi }^0$ is measured to be $(3.7\pm 0.9(stat)\pm 0.3(syst))\times {10}^{-6}$ for $E_{\gamma }^{\ast }>10\text{MeV}$. The branching ratio, $\gamma$ energy spectrum and angular distribution are consistent with ChPT prediction.