Study of $K^+ rightarrow pi^{0} e^{+} u gamma $ decay with OKA setup

Results of a study of the $K^+ rightarrow pi^{0} e^{+} u gamma $ decay at OKA setup are presented. More than 32000 events of this decay are observed. The differential spectra over the photon energy and the photon-electron opening angle in kaon rest frame are presented. The branching ratios, normalized to that of $K_{e3}$ decay are calculated for different cuts in $E^*_gamma$ and $cosTheta^{*}_{egamma}$. In particular, the branching ratio for $E^{*}_{gamma}>30$ MeV and $Theta^{*}_{e gamma}>20^{circ}$ is measured R = $frac{Br(K^+ rightarrow pi^{0} e^{+} u_{e} gamma) } {Br(K^+ rightarrow pi^{0} e^{+} u_{e})} $ = =(0.587$pm$0.010($stat.$)$pm$0.015($syst.$))$times10^{-2}$, which is in a good agreement with ChPT $O(p^{4})$ calculations.