Superheavy particle origin of IceCube PeV neutrino events

We interpret the PeV shower events observed by the IceCube Collaboration as an s-channel enhancement of neutrino-quark scattering by a leptoquark that couples to the τ-flavor and light quarks. With a leptoquark mass around 0.6 TeV and a steep 1/E2.3 neutrino flux, charged-current scattering gives cascade events at ∼1 PeV and neutral-current scattering gives cascade events at ∼0.5 PeV. This mechanism is also consistent with the paucity of muon-track events above 100 TeV.