Bounds on Low Scale Gravity from RICE data and Cosmogenic Neutrino Flux Models

Abstract

We explore limits on low scale gravity models set by results from the Radio Ice Cherenkov Experiment's (RICE) ongoing search for cosmic ray neutrinos in the cosmogenic, or GZK, energy range. The bound on M_D, the fundamental scale of gravity, depends upon cosmogenic flux model, black hole formation and decay treatments, inclusion of graviton mediated elastic neutrino processes, and the number of large extra dimensions, d. Assuming proton-based cosmogenic flux models that cover a broad range of flux possibilities, we find bounds in the interval 0.9 TeV <M_D< 10 TeV. Heavy nucleus-based models generally lead to smaller fluxes and correspondingly weaker bounds. Values d = 5, 6 and 7, for which laboratory and astrophysical bounds on LSG models are less restrictive, lead to essentially the same limits on M_D.