Speaker
Description
The observation of neutrino flavor oscillations marks the dawn of a new era in neutrino physics: the era of massive (and decaying) neutrinos. Neutrinos produced by core-collapse Supernova explosions open the possibility to simultaneously study, together with the mechanism driving the stellar explosion, also neutrinos properties, as their mass and lifetime. The next-generation water Cherenkov Hyper-Kamiokande detector will be able to detect thousands of neutrino events from a galactic Supernova explosion via Inverse Beta Decay processes followed by neutron capture on Gadolinium. This superb statistics provides a unique window to set bounds on these neutrino properties via the time delay and the flux suppression induced in the Supernovae neutrino time and energy spectra. Special attention should be devoted to the statistically sub-dominant elastic scattering induced events, which can substantially improve the neutrino mass bound via time delays. When allowing for a invisible decaying scenario, the $95\%~$C.L. lower bound on $\tau/m$ is almost one order of magnitude better than the one found with SN1987A neutrino events. Simultaneous limits can be set on both $m_\nu$ and $\tau_{\nu}$, combining the neutrino flux suppression with the time-delay signature. The tightest $95\%~$C.L. bounds on the neutrino mass found results to be competitive with the tightest neutrino mass limits nowadays, but also comparable to future laboratory direct mass searches.
