Speaker
Description
Discovering neutrino decay would be strong evidence of new physics. Presently, there are only lax lower limits on the lifetime $\tau$ of neutrinos, of $\tau/m > 10^{-3}$ s eV$^{-1}$ or worse, where $m$ is the neutrino mass. Fortunately, TeV-PeV cosmic neutrinos offer superior sensitivity to decay due to their cosmological-scale baselines. We employ a promising method, recently proposed, that uses the Glashow resonance $\bar{\nu}_e + e \to W$, triggered by $\bar{\nu}_e$ of 6.3 PeV, to test decay with only a handful of detected events. Based on the recent detection of the first Glashow resonance candidate in IceCube, we place new lower limits on the lifetimes of $\nu_1$ and $\nu_2$ in the inverted mass ordering. For $\nu_2$, our limit is the current best. For $\nu_1$, our limit is close to the current best and will surpass it soon.
Mini-abstract
The first Glashow resonance candidate disfavors neutrino decay in the inverted mass ordering