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.
• Language: unknown
• Published: 2012
• Subjects: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS; GENERAL PHYSICS; ANTENNAS; COSMIC NEUTRINOS; EXTENSIVE AIR SHOWERS; NEUTRINOS; PHYSICS; TRANSIENTS; Antarctic; The Antarctic; Antarc*
• Online Access: http://www.osti.gov/servlets/purl/1030510; https://www.osti.gov/biblio/1030510

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.