EeV neutrinos associated with UHECR sources

Electromagnetic energy losses of charged pions and muons suppress the expected high energy, ≥ 1018 eV, neutrino emission from sources of ultrahigh energy, > 1019 eV, cosmic-rays. We show here that > 1019 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 μ± 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 theWaxman-Bahcall bound. Their detection may allow one to directly identify the sources of > 1019 eV cosmic-rays, and will provide the most stringent constraints on quantum-gravity-induced Lorentz violation.