Neutrino non-radiative decay and the diffuse supernova neutrino background

Abstract: We revisit the possibility that neutrinos undergo non-radiative decay. We investigate the potential to extract information on the neutrino lifetime-to-mass ratio from the diffuse supernova neutrino background. To this aim, we explicitly consider the current uncertainties on the core-collapse supernova rate and the fraction of failed supernovae. We present predictions in a full 3 neutrino framework in the absence and presence of neutrino non-radiative decay, for the Super-Kamiokande+Gd, the JUNO, the Hyper-Kamiokande, and the DUNE experiments, that should observe the diffuse supernova neutrino background in the near future. Our results show the importance of a 3 neutrino treatment of neutrino decay and of identifying the neutrino mass ordering to break possible degeneracies between DSNB predictions in the presence of decay and standard physics.