Cosmic UHE neutrino signatures

Utilizing the unique and reliable ultrasmall-x predictions of the dynamical (radiative) parton model, nominal event rates and their detailed energy dependence caused by a variety of cosmic UHE neutrino fluxes are calculated and analyzed. In addition, maximal Regge-model inspired small-x structure functions are employed for obtaining optimal rates which do not necessarily require ‘new’ physics interpretations. Upward μ++μ− event rates are estimated by taking into account total and nadir-angle dependent regeneration effects due to neutral current interactions. For exploring extragalactic neutrino sources at highest energies (≳108 GeV) with modern (future) ground-level telescopes, we analyze horizontal air shower event rates and shower events caused by Earth-skimming tau-neutrinos, in particular their detailed shower- and cosmic neutrino-energy dependence. As an illustration of ‘new physics’ implications we estimate the relevant horizontal air shower event rates due to spin-2 Kaluza–Klein ‘graviton’ exchanges in neutral current neutrino-quark and neutrino–gluon interactions at low TeV-scales.