Heavy neutrino decay at SHALON

V.G. Sinitsyna, M. Masip, V.Y. Sinitsyna, U. Gensch, M. Walter
2013 EPJ Web of Conferences  
The SHALON Cherenkov telescope has recorded over 2 × 10 6 extensive air showers during the past 17 years. The analysis of the signal at different zenith angles has included observations from the sub-horizontal direction Θ = 97 • . This inclination defines an Earth skimming trajectory with 7 km of air and around 1000 km of rock in front of the telescope. During a period of 324 hours of observation, after a cut of shower-like events that may be caused by chaotic sky flashes or reflections on the
more » ... now of vertical showers, we have detected 5 air showers of TeV energies. We argue that these events may be caused by the decay of a long-lived penetrating particle entering the atmosphere from the ground and decaying in front of the telescope. We show that this particle can it not be a muon or a tau lepton. As a possible explanation, we discuss two scenarios with an unstable neutrino of mass m ≈ 0.5 GeV and cτ ≈ 30 m. Remarkably, one of these models has been recently proposed to explain an excess of electron-like neutrino events at MiniBooNE.
doi:10.1051/epjconf/20125209010 fatcat:syxm6glpvjdgjgmu7myxt465c4