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

ABREU, P.; AGLIETTA, M.; AHN, E; GARCIA, B (400 AUTORES ORDEN ALFABETICO)

PHYSICAL REVIEW D

AMER PHYSICAL SOC

Año: 2011 vol. 84 p. 1 - 16

1550-7998

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 airshowers. 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 thewater-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 computethe 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 EÀ2 differential energy spectrum the limit onthe single-flavor neutrino is E2 dN=dE < 1:74 Â 10À7 GeVcmÀ2 sÀ1 srÀ1 at 90% C.L. in the energy range 1 Â 1017 eV < E < 1 Â 1020 eV.