How Unequal Fluxes of High Energy Astrophysical Neutrinos and Antineutrinos can Fake New Physics

Understand

Flavor ratios of very high energy astrophysical neutrinos, which can be studied at the Earth by a neutrino telescope such as IceCube, can serve to diagnose their production mechanism at the astrophysical source.

• The flavor ratios for neutrinos and antineutrinos can be quite different as we do not know how they are produced in the astrophysical environment.
• Due to this uncertainty the neutrino and antineutrino flavor ratios at the Earth also could be quite different.
• Nonetheless, it is generally assumed that flavor ratios for neutrinos and antineutrinos are the same at the Earth, in fitting the high energy astrophysical neutrino data.