Search for ultra-high energy neutrinos at the pierre auger observatory

¹ Dpto. de Física Teórica y del Cosmos & C.A.F.P.E., Universidad de Granada, 18071 Granada, Spain
² Av. San Martín Norte 304 (5613) Malargüe, Prov. de Mendoza, Argentina

^a e-mail: navas@ugr.es

Abstract

The observation of ultra-high energy neutrinos (UHEνs) has become a priority in experimental astroparticle physics. UHEνs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ν) or in the Earth's crust (Earth-skimming ν), producing air showers that can be observed with arrays of detectors at the ground. With the Surface Detector Array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground.In this paper we review the procedure and criteria established to search for UHEνs in the data collected with the surface array of the Pierre Auger Observatory. No neutrino candidates have so far been found, which allows us to place competitive limits to the diffuse flux of UHEνs with energies between ∼10¹⁷eV and ∼10²⁰eV. Moreover, upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. We show that with the Surface Detector of the Pierre Auger Observatory we are sensitive to a large fraction of the sky spanning ∼100^∘ in declination.