Speaker
Description
The KM3NeT collaboration recently reported the observation of KM3-230213A, a neutrino event with an energy of 220 PeV, $\mathcal{O}(10)$ times more energetic than the highest-energy neutrino in IceCube’s catalog. Despite its larger effective area and longer data-taking period, IceCube has not observed similar events, leading to a tension quantified between ~2$\sigma$ and 3.5$\sigma$, depending on the type of neutrino source.
The 220 PeV neutrino detected at KM3NeT has traversed approximately 147 km through rock and sea, whereas neutrinos from the same location in the sky would cross only about 14 km of ice to reach IceCube. In this talk, I will show how differences in propagation distance can help resolve this tension by presenting a scenario where sterile to active neutrino oscillation is amplified in the presence of matter. I will present two mechanisms: one where a new matter potential induces a resonance in sterile-to-active transitions, and another involving off-diagonal neutrino non-standard interactions. In both cases, oscillations over ~100 km enhance the active neutrino flux at KM3NeT with respect to the flux at IceCube. We also investigate whether the same mechanism could explain the ANITA anomaly, hinting towards a common origin of new physics. Overall, we propose the possibility that neutrino telescopes have already started detecting signatures of physics beyond the Standard Model.
