In a new paper, I place new limits on the lifetime of the nu_1 and nu_2 neutrinos, assuming they decay into a visible nu_3, in the inverted neutrino mass ordering:
New limits on neutrino decay from the Glashow resonance of high-energy cosmic neutrinos
To place my new limts, I put to practice a proposal that we published earlier (1610.02096), that uses the observation of the Glashow resonance in IceCube, at a few PeV, as evidence of the survival of nu_1 and nu_2.
I base our present-day results on the observation of the first Glashow resonance candidate by IceCube. For nu_2, the limit on the lifetime is the best one to date. For nu_1, it is comparable to the best one to date, coming from solar neutrinos. The limits quickly improve with just a handful more of Glashow resonances observed.