Abstract and subjects
The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E-nu between 10(17) eV and 10(20) eV from point-like sources across the sky south of +55 degrees and north of -65 degrees declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of similar to 3.5 years of a full surface detector array for the Earth-skimming channel and similar to 2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k(PS) . E-nu(-2). from a point-like source, 90% confidence level upper limits for k(PS) at the level of approximate to 5x10(-7) and 2.5x10(-6) GeV cm(-2) s(-1) have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively. RI Petrolini, Alessandro/H-3782-2011; Albuquerque, Ivone/H-4645-2012; Chinellato, Carola Dobrigkeit /F-2540-2011; Muller, Marcio Aparecido/H-9112-2012; D'Urso, Domenico/I-5325-2012; Badescu, Alina/B-6087-2012; Bleve, Carla/J-2521-2012; martello, daniele/J-3131-2012; Valino, Ines/J-8324-2012; Brogueira, Pedro/K-3868-2012; de souza, Vitor/D-1381-2012; Alves Batista, Rafael/K-6642-2012; Chinellato, Jose Augusto/I-7972-2012; Yushkov, Alexey/A-6958-2013; Falcke, Heino/H-5262-2012; Beatty, James/D-9310-2011; Ebr, Jan/H-8319-2012; Anjos, Joao/C-8335-2013; Fauth, Anderson/F-9570-2012; Sarkar, Subir/G-5978-2011; Caramete, Laurentiu/C-2328-2011 OI D'Urso, Domenico/0000-0002-8215-4542; Brogueira, Pedro/0000-0001-6069-4073; Falcke, Heino/0000-0002-2526-6724; Ebr, Jan/0000-0001-8807-6162; Sarkar, Subir/0000-0002-3542-858X;
The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E ν between 1017 eV and 1020 eV from point-like sources across the sky south of +55° and north of -65° declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of ~3.5 years of a full surface detector array for the Earth-skimming channel and ~2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k PS · E -2 ν from a point-like source, 90% confidence level upper limits for k PS at the level of ≈5 × 10-7 and 2.5 × 10-6 GeV cm-2 s-1 have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively.