Measurement of direct photon emission in $K^{+}\to {\pi }^{+}{\pi }^0\gamma$ decay using stopped positive kaons

Abstract

The radiative decay $K^{+}\to {\pi }^{+}{\pi }^0\gamma$ ($K_{\pi 2\gamma }$) has been measured with stopped positive kaons. A $K_{\pi 2\gamma }$ sample containing 4k events was analyzed, and the $K_{\pi 2\gamma }$ branching ratio of the direct photon emission process was determined to be $[6.1\pm 2.5(\mathrm{stat})\pm 1.9(\mathrm{syst})]\times 10^{-6}$. No interference pattern with internal bremsstrahlung was observed.

12 pages, 6 figures, 2 tables, to be published in Phys. Lett. B