Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

• Published in: Physical review letters Vol. 100; no. 21; p. 211101
• Main Authors: Abraham, J, Abreu, P, Aglietta, M, Aguirre, C, Allard, D, Allekotte, I, Allen, J, Allison, P, Alvarez-Muñiz, J, Ambrosio, M, Anchordoqui, L, Andringa, S, Anzalone, A, Aramo, C, Argirò, S, Arisaka, K, Armengaud, E, Arneodo, F, Arqueros, F, Asch, T, Asorey, H, Assis, P, Atulugama, B S, Aublin, J, Ave, M, Avila, G, Bäcker, T, Badagnani, D, Barbosa, A F, Barnhill, D, Barroso, S L C, Bauleo, P, Beatty, J J, Beau, T, Becker, B R, Becker, K H, Bellido, J A, BenZvi, S, Berat, C, Bergmann, T, Bernardini, P, Bertou, X, Biermann, P L, Billoir, P, Blanch-Bigas, O, Blanco, F, Blasi, P, Bleve, C, Blümer, H, Bohácová, M, Bonifazi, C, Bonino, R, Boratav, M, Brack, J, Brogueira, P, Brown, W C, Buchholz, P, Bueno, A, Burton, R E, Busca, N G, Caballero-Mora, K S, Cai, B, Camin, D V, Caramete, L, Caruso, R, Carvalho, W, Castellina, A, Catalano, O, Cataldi, G, Cazon, L, Cester, R, Chauvin, J, Chiavassa, A, Chinellato, J A, Chou, A, Chye, J, Clark, P D J, Clay, R W, Colombo, E, Conceição, R, Connolly, B, Contreras, F, Coppens, J, Cordier, A, Cotti, U, Coutu, S, Covault, C E, Creusot, A, Criss, A, Cronin, J, Curutiu, A, Dagoret-Campagne, S, Daumiller, K, Dawson, B R, de Almeida, R M, De Donato, C, de Jong, S J, De La Vega, G, de Mello Junior, W J M, de Mello Neto, J R T
• Format: Journal Article
• Language: English
• Published: United States American Physical Society 30-05-2008
• Subjects: Astrophysics; CASCADE SHOWERS; CHARGED-CURRENT INTERACTIONS; Cosmology and Extra-Galactic Astrophysics; EARTH ATMOSPHERE; EARTH CRUST; EEV RANGE; ENERGY SPECTRA; Physics; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Sciences of the Universe; TAU NEUTRINOS; TAU PARTICLES; and other elementary particles; muon; cosmic ray detectors; and other elementary particle detectors; pion; Cosmic rays; Neutrino
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.100.211101

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.