Signals of HE atmospheric muon decay in flight around the Sun's albedo versus astrophysical muon and tau neutrino traces in the Moon's shadow

Abstract

The Sun albedo of cosmic rays at GeVs energy has been discovered recently by FERMI satellite. They are traces of atmospheric CR hitting solar atmosphere and reflecting skimming gamma photons. Even if relevant for astrophysics, as being trace of atmospheric solar Cosmic Ray noises they cannot offer any signal of neutrino astronomy. On the contrary the Moon, with no atmosphere, may become soon a novel filtering calorimeter and an amplifier of energetic muon astronomical neutrinos (at TeV up to hundred TeV energy); these lepton tracks leave an imprint in their beta decay while in flight to Earth. Their TeV electron air-shower are among the main signals. Also a more energetic, but more rare, PeV up to EeV tau lunar neutrino events may be escaping as a tau lepton from the Moon: PeVs secondaries may be shining on Earth atmosphere in lunar shadows in a surprising rich way. One or a few gamma air-shower event inside the Moon shadows may occur each year in near future CTA or LHAASO TeVs gamma array detector, assuming a non negligible astrophysical TeV up to hundred TeV neutrino component (respect to our terrestrial ruling atmospheric ones); these signals will open a new wonderful passepartout keyhole for neutrino been seen along the Moon. The lunar solid angle is small and the muon or tau expected rate is rare, but future largest tau radio array as GRAND one might well discover such neutrino imprint.