Measurement of T-odd asymmetry in radiative K+ -> pi0 e+ nu gamma decay using OKA detector

Abstract

The paper presents a measurement of the T-odd correlation in radiation decay \boldmath $K^+ \rightarrow \pi^{0} e^{+} \nu_{e} \gamma $ performed on the installation of the 101200 candidate events of the investigated decay were identified. Measured correlation $\xi_{\pi e \gamma}$ -is a mixed product of moments $e^{+}$, $\pi^{0}$, $\gamma$ in the kaon rest system, normalized by $M^{3}_{K}$. To assess the asymmetry of the distribution by $\xi_{\pi e \gamma}$ the value used is $A_{\xi}= \frac {N_{+}-N_{-}} {N_{+}+N_{-}}$, where $N_{+(-)}$ is the number of events with $\xi$ greater than (less than) zero. For the $A_{\xi}$ asymmetry, the value is obtained $A_{\xi} = (+0.1 \pm 3.9($stat.$) \pm1.7($syst.$))\times10^{-3}$ or $|A_{\xi}| < 5.4\times10^{-3} (90\%~ CL)$