Abstract
The \(K^{+}\to\pi^{0}\mu^{+}\nu\gamma\) ( \(K_{\mu 3\gamma}\) ) decay is measured with OKA detector at the RF-separated 17.7 GeV/c momentum kaon beam from the U-70 synchrotron. The data obtained corresponds to the value of \(2.62\times 10^{10}\) ‘‘live’’ kaons passing to the decay volume. About 1000 \(K_{\mu 3\gamma}\) events are extracted. The ratio of \(\textrm{Br}(K_{\mu 3\gamma})/\textrm{Br}(K_{\mu 3}\) ) is measured. The T-odd correlation \({\xi}_{\pi\mu\gamma}\) , which is the mixed product of the momenta of \(\mu^{+},\pi^{0}\) , and \(\gamma\) in the kaon rest frame, is measured. The asymmetry of the distribution in \(\xi\) is characterized by the ratio \(A_{\xi}=(N_{+}-N_{-})/(N_{+}+N_{-})\) , where \(N_{+}\) ( \(N_{-}\) ) is the number of events with positive (negative) \(\xi\) . The values of \(A_{\xi}\) is obtained. Our results are preliminary, with systematic errors being estimated.
