Heavy-neutrino decays at neutrino telescopes

It has been recently proposed that a sterile neutrino νh of mass mh=40-80 MeV, mixing |Uμh|2≅10-3-10-2, lifetime τh≤10-9 s, and a dominant decay mode νh→νγ could be the origin of the experimental anomalies observed at LSND and MiniBooNE. Such a particle would be abundant inside air showers, as it can be produced in kaon decays. We use the Z-moment method to evaluate its atmospheric flux and the frequency of its decays inside neutrino telescopes. We show that νh would imply around 104 contained showers of energy between 0.1 and 100 TeV per year inside a 0.03 km3 telescope like ANTARES or the DeepCore in IceCube, while the standard background is 100 times smaller. Therefore, although it may be challenging from an experimental point of view, a search there could confirm this heavy-neutrino possibility.