Speaker
Description
The IceCube Neutrino Observatory recently published evidence for diffuse neutrino emission from the Galactic Plane at $4.5\sigma$ significance. This new source of astrophysical neutrinos provides an exciting laboratory for probing the nature of neutrino masses. In particular, extremely small mass splittings, such as those predicted by quasi-Dirac neutrino mass models, and finite neutrino lifetimes from neutrino decays, would induce effects on the spectra and flavor ratios of neutrinos with TeV-scale energies traversing kiloparsec-scale baselines. Using TANDEM, a new three dimensional galactic neutrino emission model, we explore the sensitivity of IceCube and KM3NeT/ARCA to these ultra-long baseline phenomena. We find that a combined analysis would be sensitive to as-yet unexplored regions of parameter space in both quasi-Dirac and decay scenarios; the sensitive region to quasi-Dirac parameter space is $10^{-15}~\mathrm{eV^2} \lesssim \delta m^2 \lesssim 10^{-10}~\mathrm{eV^2}$, and the sensitive region to invisible neutrino decay is $m / \tau \gtrsim 10^{-15.5}~\mathrm{eV^2}$. Our results demonstrate the potential that astrophysical neutrino sources and global neutrino telescope networks have in probing new regions of exotic neutrino mass models.
