Using IceCube to Search for Diffuse Neutrino Fluxes at Ultra-High Energies

University Of California-Irvine, Irvine CA

Investigators

Abstract

At high energies, only neutrinos can directly convey astrophysical information from the most distant reaches of the Universe or from deep inside the most cataclysmic, breathtakingly powerful, regions yet identified. Neutrinos provide a unique view of how nature accelerates particles and can clarify the role of hadrons in the astrophysical milieu. With 59 (out of 80) IceCube strings deployed since January 2005, the IceCube collaboration is poised to advance the state-of-the-art by a significant margin. This award will provide funds to accelerate the advance of the scientific frontier by developing and extending data analysis and simulation tools to search for a diffuse flux of Ultra-High Energy (UHE) neutrinos using the IceCube Observatory. The proposed work will develop event reconstruction code and will investigate new procedures to reconstruct events by taking advantage of the information contained within the complete waveform record. Their proposed research plan includes simulation studies of UHE neutrino events in IceCube using a supercomputer cluster and they have started to investigate the performance at UHE energies. They have been approved for 500,000 cpu hours on the Teragrid clusters. Two years of IceCube data should improve current flux limits by a factor of 4 since little background remains in the UHE analysis. If no signal is found, then the flux limits will be less than any version of the Waxman-Bahcall bound, which implies that cosmic ray accelerators must be less efficient at producing neutrinos. The broader impacts of this proposal provide an outlet for curiosity and imagination driven research by graduate and postdoctoral students who will be given the opportunity to learn about data acquisition electronics, detector simulation, and data processing. Student training is founded on strong mentorship.