Date and time:  Wednesday March 26th, 2025 at 16:00 CET

Speaker:  Shirley Li (University of California, Irvine)

Title: Clash of the Titans: Ultra-High Energy KM3NeT Event Versus IceCube Data.

Astract: KM3NeT has reported the detection of a remarkably high-energy through-going muon, KM3-230213A. Lighting up approximately one-third of the detector, this muon likely originated from a neutrino exceeding 10 PeV in energy. The crucial question we need to address is the origin and source of KM3-230213A. Intriguingly, IceCube has been operating with a much larger effective area for a considerably longer time, yet it has not reported neutrinos above 10 PeV.

In this talk, I will discuss the possible origin of KM3-230213A by quantifying the tension between this event and the absence of similar high-energy events in IceCube. Our analysis reveals a tension of 3.0-3.5 sigma for various underlying source assumptions. The lack of observation of high-energy events in IceCube seriously challenges the explanation of this event originating from any known diffuse fluxes. Additionally, I will compare our results to official KM3NeT analyses

Slides: files/HiDDeN_Li.pdf