Sterile neutrino decay explanation of LSND and MiniBooNE anomalies

We examine a recently proposed explanation of the liquid scintillator neutrino detector and MiniBooNE anomalies, given in terms of a sterile neutrino N of the mass 40MeV less than or similar to mN less than or similar to 80MeV mixed with nu(mu) at the strength 10(-3) less than or similar to vertical bar U-mu N vertical bar(2) less than or similar to 10(-2) and which dominantly decays into a light neutrino and photon: N -> nu mu We check compatibility of this scenario with the existing experimental data on radiative tau-lepton and K-meson decays. We find that neither of these data are able to totally rule out the above indicated region of m(N) - vertical bar U-mu N vertical bar(2). However, we show that the current experimental data on K -> mu nu gamma decay exclude a significant part of this region. We propose experimental cuts on this decay allowing to improve its sensitivity to the region in question. We also show that measurements of K K -> mu nu ee decay have good prospects for testing the decaying sterile neutrino scenario.