New Limits on the Ultra-High Energy Cosmic Neutrino Flux from the ANITA Experiment

• Main Authors: Gorham, P. W., Allison, P., Barwick, S. W., Beatty, J. J., Besson, D. Z., Binns, W. R., Chen, C., Chen, P., Clem, J. M., Connolly, A., Dowkontt, P. F., DuVernois, M. A., Field, R. C., Goldstein, D., Goodhue, A., Hast, C., Hebert, C. L., Hoover, S., Israel, M. H., Kowalski, J., Learned, J. G.
• Other Authors: United States. Department of Energy.
• Format: Article in Journal/Newspaper
• Language: English
• Published: SLAC National Accelerator Laboratory 2011
• Subjects: Extensive Air Showers; Transients Astrophysics,Astro; Neutrinos; 71 Classical And Quantum Mechanics; General Physics; Physics; 72 Physics Of Elementary Particles And Fields; Astrophysics,Astro; Antennas; Cosmic Neutrinos; Antarctic; The Antarctic; Antarc*
• Online Access: https://digital.library.unt.edu/ark:/67531/metadc836623/

We report initial results of the first flight of the Antarctic Impulsive Transient Antenna (ANITA-1) 2006-2007 Long Duration Balloon flight, which searched for evidence of a diffuse flux of cosmic neutrinos above energies of E{sub v} = 3 x 10{sup 18} eV. ANITA-1 flew for 35 days looking for radio impulses due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. We report here on our initial analysis, which was performed as a blind search of the data. No neutrino candidates are seen, with no detected physics background. We set model-independent limits based on this result. Upper limits derived from our analysis rule out the highest cosmogenic neutrino models. In a background horizontal-polarization channel, we also detect six events consistent with radio impulses from ultrahigh energy extensive air showers.