Jefferson Lab Colloquium - Francis Halzen

On Wednesday, April 23, at 4 p.m., Francis Halzen of the University of Wisconsin-Madison will present "IceCube: The First Decade of Neutrino Astronomy and Neutrino Physics" in the CEBAF Center auditorium and via Zoom (meeting ID: 161 346 3768, passcode: 871985). Refreshments will be served in the CEBAF Center atrium at 3:30 p.m. before the presentation.

Abstract: Below the geographic South Pole, the IceCube project has transformed 1 cubic kilometer of natural Antarctic ice into a neutrino detector. IceCube detects more than 100,000 neutrinos per year in the GeV to 10 PeV energy range, providing an opportunity to test their three-flavor scenario at extreme energies and baselines. Among those, we have isolated a flux of high-energy neutrinos originating beyond our galaxy, with an energy flux that is comparable to that of the extragalactic high-energy photon flux observed by the NASA Fermi satellite. With a decade of data, we have identified their first sources, which point to supermassive black holes at the centers of active galaxies as the origin of high-energy neutrinos and high-energy cosmic rays. We recently also observed neutrinos originating in our own Milky Way, which is, interestingly, not a prominent feature in the neutrino sky.

Biography: Francis Halzen is the principal investigator of IceCube, Vilas Research Professor and Gregory Breit Professor at the University of Wisconsin-Madison, and a theoretician studying problems that span the particle physics, astrophysics and cosmology communities. In 1987, Halzen started working on the AMANDA experiment, a first-generation neutrino telescope at the South Pole that represented a proof of concept for the IceCube Neutrino Observatory. Halzen also serves on various advisory committees and review panels for astroparticle physics research and experiments.