New limits on the ultrahigh energy cosmic neutrino flux from the ANITA experiment.
/ Authors
A. Gorham, P. Allison, S. Barwick, J. Beatty, D. Besson, W. Binns, C. Chen, P. Chen, J. Clem, A. Connolly
and 46 more authors
P. Dowkontt, M. DuVernois, R. Field, D. Goldstein, A. Goodhue, C. Hast, C. Hebert, S. Hoover, M. Israel, J. Kowalski, J. Learned, K. Liewer, J. Link, E. Lusczek, S. Matsuno, B. Mercurio, C. Miki, P. Miočinović, J. Nam, C. Naudet, R. Nichol, K. Palladino, K. Reil, A. Romero-Wolf, M. Rosen, L. Ruckman, D. Saltzberg, D. Seckel, G. Varner, D. Walz, Y. Wang, F. W. U. Hawaii, UC Irvine, Ohio state Univ., U. Kansas, Washington University in St. Louis, Slac, U. Delaware, U. London, UK., Ucla, U. Minnesota, Nasajpl, National Taiwan Univ., Taipei, NASAGoddard.
/ Abstract
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(nu) approximately 3 x 10(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.
Journal: Physical review letters