EeV neutrinos associated with UHECR sources

Understand

Electromagnetic energy losses of charged pions and muons suppress the expected high energy, >1E18 eV, neutrino emission from sources of ultrahigh energy, >1E19 eV, cosmic-rays.

• We show here that >1E19 eV photons produced in such sources by neutral pion decay may escape the sources, thanks to the Klein-Nishina suppression of the pair production cross section, and produce muon pairs in interactions with the cosmic microwave background.
• The flux of muon decay neutrinos, which are expected to be associated in time and direction with the electromagnetic emission from the sources, may reach a few percent of the Waxman-Bahcall bound.
• Their detection may allow one to directly identify the sources of >1E19 eV cosmic-rays, and will provide the most stringent constraints on quantum-gravity-induced Lorentz violation.