K+ → π0µ+νγ and K+ → π0e+νγ Decays: Recent Results from the “OKA” Experiment

The K+ → π0µ+νγ(Kµ3γ) and K+ → π0e+νγ (Ke3γ) decays are 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 × 1010 “live” kaons passing to the decay volume. The ratios of Br(Kµ3γ)/Br(Kµ3) and Br(Ke3γ)/Br(Ke3) are measured. The T-odd correlation ξπμγ (ξπeγ), which is the mixed product of the momenta of µ+(e+), π0, and γ in the kaon rest frame, is measured. The asymmetry of the distribution in ξ is characterized by the ratio Aξ = (N+ − N−)/(N+ + N−), where N+(−) is the number of events with positive (negative) ξ. The values of Aξ for Kµ3γ and for Ke3γ is obtained.