Decays of Long-Lived Relics and Their Signatures at IceCube.
We consider long-lived relic particles as the source of the PeV-scale neutrinos detected at the IceCube observatory over the last six years. We derive the present day neutrino flux, including primary neutrinos from direct decays, secondary neutrinos from electroweak showering, and tertiary neutrinos from re-scatters off the relic neutrino background. We compare the high-energy neutrino flux prediction to the most recently available datasets and find qualitative differences to expected spectra from other astrophysical processes. We utilize EW corrections to constrain heavy decaying relic abundances, using measurements impacted by EM energy injection, such as light element abundances during BBN, CMB anisotropies, and diffuse $\gamma$-ray spectra. We compare these abundances to those necessary to source the IceCube neutrinos and find two viable regions in parameter space, ultimately testable by future neutrino, $\gamma$-ray, and CMB observatories.
Publisher URL: http://arxiv.org/abs/1811.04939