First results on UHE Neutrinos from the NuMoon experiment

When high-energy cosmic rays impinge on a dense dielectric medium, radio waves are produced through the Askaryan effect. At wavelengths comparable to the typical longitudinal size of showers produced by Ultra-High Energy cosmic rays or neutrinos, radio signals are an extremely efficient way to detect these particles [1]. These can be detected using the Westerbork Synthesis Radio Telescope (WSRT) which consists of fourteen 25m parabolic dishes. The low frequency band which concerns us here covers 115-170MHz. In tied-array mode the system noise at low frequencies is F_n=600Jy. To observe radio bursts of short duration, the new pulsar backend (PuMa II) is used. It provides dual-polarization baseband sampling of eight 20MHz bands. In the used configuration, four frequency bands will observe the same part of the moon with the remaining four a different section. A first analysis of the present 100 hour observations at the WSRT will be presented. O.~Scholten etal, Astropart. Phys. 26(2006)219.