trans-GZK Cosmic Rays: Strings, Black Holes, Neutrinos, or all Three?

We review the scenario in which “strongly interacting neutrinos” are responsible for inducing airshowers with inferred energies E > 8× 10 19 eV. This possibility arises naturally in string excitation models having a unification scale effectively decoupled from the Planck scale. We then show that phenomenological quantum gravity considerations reveal an equivalency of “mini-black hole” and strongly interacting neutrino pictures for explaining trans-GZK events. This equivalence can be exploited to predict single particle inclusive distributions. The resulting observable consequences in airshower development are studied using the Adaptive Longitudinal Profile Shower (ALPS) simulation.