Search for ultrahigh energy neutrinos in highly inclined events at the Pierre Auger Observatory

Authors

P. Abreu, Technical University of Lisbon
Emily B. Petermann, University of Nebraska at LincolnFollow
Gregory Snow, University of Nebraska - LincolnFollow
Pierre Auger Collaboration, Pierre Auger Collaboration

Date of this Version

2011

Citation

PHYSICAL REVIEW D 84, 122005 (2011); DOI: 10.1103/PhysRevD.84.122005

Abstract

The Surface Detector of the Pierre Auger Observatory is sensitive to neutrinos of all flavors above 0.1 EeV. These interact through charged and neutral currents in the atmosphere giving rise to extensive air showers. When interacting deeply in the atmosphere at nearly horizontal incidence, neutrinos can be distinguished from regular hadronic cosmic rays by the broad time structure of their shower signals in the water-Cherenkov detectors. In this paper we present for the first time an analysis based on down-going neutrinos. We describe the search procedure, the possible sources of background, the method to compute the exposure and the associated systematic uncertainties. No candidate neutrinos have been found in data collected from 1 January 2004 to 31 May 2010. Assuming an E^-2 differential energy spectrum the limit on the single-flavor neutrino is E²dN=dE-7GeVcm^-2s^-1sr^-1 at 90% C.L. in the energy range 1 X 10¹⁷eV< E 10²⁰eV.