New physics potential with a neutrino telescope

Active Galactic Nuclei are considered as sources of neutrinos, with neutrino energies extending up to 1018 eV. It is expected that these highly energetic cosmic neutrinos will be detected by the neutrino telescopes, presently under construction. The detection process is very sensitive to the total νμN cross-section. We examine how σtot(νμN) changes at high energies, by the single production of excited fermions (μ∗, νμ∗). For parameters (masses, couplings) of the excited fermions allowed by the experimental constraints, we find that for energies of the incoming νμ above 100 TeV the cross-section for single production of μ∗, νμ∗ supersedes the standard total cross-section.