Wednesday, November 2, 2016
The discovery of a diffuse flux of astrophysical neutrinos above 10 TeV at the IceCube Neutrino Observatory has opened not only a new window for astronomy but also fundamental particle physics. I will discuss two recent measurements from IceCube and their implications for particle physics. The first, a measurement of the flavor composition of astrophysical neutrinos, probes the environment at the cosmic accelerators producing high-energy neutrinos but also may reveal exotic physics such as neutrino decay and Lorentz violation. The second measurement uses the attenuation of atmospheric and astrophysical neutrinos in the Earth to place the first constraints on the neutrino-nucleon cross section at energies more than two orders of magnitude larger than available at accelerator facilities. Lastly, I will mention the potential of future experiments, such as IceCube-Gen2 and ARIANNA, to improve upon these measurements.