Heavy-neutrino decays at neutrino telescopes

Understand

It has been recently proposed that a sterile neutrino \nu_h of mass m_h=40--80 MeV, mixing |U_{\mu h}|^2=10^{-3}--10^{-2}, lifetime \tau_h \lsim 10^{-9} s, and a dominant decay mode (\nu_h \to \nu_\mu \gamma) could be the origin of the experimental anomalies observed at LSND, KARMEN and MiniBooNE.

• Such a particle would be abundant inside air showers, as it can be produced in kaon decays (K -> \nu_h \mu, K_L -> \nu_h \pi \mu).
• We use the Z-moment method to evaluate its atmospheric flux and the frequency of its decays inside neutrino telescopes.
• We show that the \nu_h would imply around 10^4 contained showers per year inside a 0.03 km^3 telescope like ANTARES or the DeepCore in IceCube.