Speaker
Description
We demonstrate the possibility of testing Heavy Neutral Leptons (HNLs) using "cosmic ray beam-dumps'' : setups where high-energy incident cosmic rays impinge on the Earth's atmosphere and then on the Earth's surface. We focus on HNL production from atmospherically produced parent meson decays, and examine them as a possible explanation of the appearing Cherenkov showers observed by the SHALON Cherenkov telescope and the ultra-high energy events detected by the ANITA neutrino experiment. Further, we propose two new experimental setups with improved sensitivities, namely a Cherenkov telescope pointing at a sub-horizontal angle and shielded by the mountain cliff at Mt. Thor, and SPYGLASS: a geostationary satellite that observes part of the Sahara desert. Our results show that that the Mt. Thor experiment can probe currently untested HNL parameter space below the kaon mass; while SPYGLASS can significantly increase the HNL parameter space coverage in the mass range from 10 MeV up to 2 GeV and test neutrino mixing $|U_{\alpha4}|^2$ down to $10^{-11}$ for masses around 300 MeV.
