Limits on the Ultra-High Energy Electron Neutrino Flux from the RICE Experiment

Upper limits are presented on the diffuse flux of ultra-high energy $\nu_e$, based on analysis of data taken by the RICE experiment during August, 2000. The RICE receiver array at South Pole monitors cold ice for radio-wavelength Cherenkov radiation resulting from neutrino-induced in-ice showers. For energies above 1 EeV, RICE is an effective detector of over 15 km$^3$ sr. Potential signal events are separated from backgrounds using vertex location, event reconstruction, and signal shape. These are the first terrestrial limits exploiting the physics of radio Cherenkov emissions from charged-current $\nu_e+N\to e+N'$ interactions.