Study of \(\boldsymbol{K}^{\boldsymbol{+}}{\rightarrow}{\pi}^{\mathbf{0}}\boldsymbol{e}^{\boldsymbol{+}}{\nu}{\gamma}\) Decay with OKA Setup

Abstract

Results of study of the \(K^{+}\rightarrow\pi^{0}e^{+}\nu\gamma\) decay at OKA setup are presented. More than 150K candidates for this decay have been selected. The branching ratios, normalized to that of \(K_{e3}\) decay are calculated for different cuts on \(E^{*}_{\gamma}\) and \(\Theta^{*}_{e\gamma}\). In particular, the branching ratio for \(E^{*}_{\gamma}>30\) MeV and \(\Theta^{*}_{e\gamma}>20^{\circ}\) is measured \(\textrm{R}=\frac{Br(K^{+}\rightarrow\pi^{0}e^{+}\nu_{e}\gamma)}{Br(K^{+}\rightarrow\pi^{0}e^{+}\nu_{e})}=(0.610\pm 0.007(\textrm{stat.})\pm 0.011(\textrm{syst.}))\times 10^{-2}\), which is in a good agreement with ChPT \(O(p^{6})\) calculations.