| Number | R7-3 / IPMU/ILANCE/ICRR joint seminar |
| Date&Time | October 2, 2025. Thu. 15:30- |
| Place | ICRR 6F, Large Seminar Room Zoom: https://u-tokyo-ac-jp.zoom.us/j/86096780466?pwd=RWzJSknDZ2e5ORqMNQNuRvgfaH00NJ.1 |
| Speaker | Maximilian Meier (Chiba University) |
| Title | “Neutrinos at the Highest Energies: IceCube’s Window into Ultra-High-Energy Cosmic Rays” |
| Abstract | Ultra-high-energy cosmic rays (UHECRs) produce astrophysical neutrinos (TeV+) inside their sources and so-called cosmogenic neutrinos (PeV+) on their journey through the universe. These neutrinos are unique messengers from the distant and violent universe, able to probe the sources of UHECRs. The IceCube Neutrino Observatory is the largest neutrino detector in the world, instrumenting a cubic kilometer of Antarctic ice to catch these rare and elusive particles. In this talk, after briefly reviewing IceCube’s recent studies of astrophysical neutrinos, I will present IceCube’s world leading limit on the neutrino flux at the highest energies. For the first time the non-observation of cosmogenic neutrinos puts serious constraints on the composition of UHECRs. Finally, I put IceCube’s limit into context of the recent observation of an extremely-high-energy neutrino in KM3NeT. |
