An upper limit to the photon fraction in cosmic rays above 1019 eV from the Pierre Auger Observatory

  title={An upper limit to the photon fraction in cosmic rays above 1019 eV from the Pierre Auger Observatory},
  author={Jeena P Abraham and Michel Aglietta and Catalina Aguirre and Denis Allard and I. Allekotte and P. Allison and Camilo Alvarez and Jaime Alvarez-Mu{\~n}iz and Michelangelo Ambrosio and Luis Alfredo Anchordoqui and Bồ and J. C. dos Anjos and Carla Aramo and Katsushi Arisaka and Eric Armengaud and Fabrizio Arneodo and Fernando Arqueros and T. W. J. Van Asch and Hern{\'a}n Asorey and B. S. Atulugama and J. Aublin and Gimena Avila and Jeferson Bacelar and Tobias B{\"a}cker and Daniel Badagnani and Ademarlaudo F. Barbosa and Henrique M J Barbosa and Matthias Barkhausen and Danny Barnhill and Soraya Coelho Costa Barroso and Pablo Bauleo and James Beatty and Tristan Beau and Bryan R. Becker and Kurt H. Becker and J. A. Bellido and Corinne B{\'e}rat and Paolo Bernardini and Xavier Bertou and P. L. Biermann and Pierre Billoir and O. Blanch-Bigas and Pasquale Blasi and Carla Bleve and H. J. Bl{\"u}mer and Pedram Boghrat and Martina Boh{\'a}{\vc}ov{\'a} and Corrado Bonifazi and Raffaella Bonino and M. Boratav and Janet Brack and Bu and J-M. Brunet and Peter Buchholz and K. S. Caballero-Mora and Bin Cai and Jillian N. Capdevielle and Antonella Castellina and Gianni Cataldi and L. Caz{\'o}n and R. Cester and Jo{\"e}l Chauvin and Andrea Chiavassa and Jos{\'e} A. Chinellato and Amanda Chou and Roger W. Clay and Stephen B. Clay and B. Connolly and Adeline Cordier and Umberto Cotti and B. R. Dawson and Rafael de Almeida and Litia Alves de Carvalho and W. J. M. de Mello and Jo{\~a}o R. T. de Mello Neto and Ivan De Mitri and M. A. Leigui de Oliveira and Vitor De Souza and Maŕıa Teresa Dova and L. N. Epele and Carlos O. Escobar and Agustina Etchegoyen and Alberto Filevich and Jean-Philippe Gitto and Federico Gobbi and F A G{\'o}mez Albarrac{\'i}n and Mariano Gomez Berisso and R. G{\'o}mez ‐ Herrero and Margarida D Amaral and Jaime Gongora and P. Gouffon and Christian Grunfeld and Germano P. Guedes},
An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies greater than 10 eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger… CONTINUE READING

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Z. Fodor, S. D. Katz
Rev. Lett. 86 (2001) 3224; S. Sarkar, R. Toldra, Nucl. Phys. B621 (2002) 495; C. Barbot, M. Drees, Astropart. Phys. 20 (2003) 5; R. Aloisio, V. Berezinsky, M. Kachelrieß, Phys. Rev. D 69 • 2004
View 5 Excerpts
Highly Influenced


S. Ostapchenko
Phys. B 151 (Proc. Suppl.) • 2006
View 3 Excerpts
Highly Influenced

G: Nucl

T. C. Rogers, M. I. Strikman, J. Phys
Part. Phys. 32 • 2006
View 1 Excerpt


M. Nagano, A. A. Watson
Mod. Phys. 72 (2000) 689; M. Boratav, G. Sigl, C.R. Physique (Eds.), Ultimate Energy Particles in the Universe, vol. 5, Elsevier, Paris, 2004; J. Cronin, Nucl. Phys. B, Proc. Suppl. 138 • 2005

Acta Phys

S. Sarkar
Polon. B35 • 2004
View 1 Excerpt

Nauk SSSR 92 ( 1953 ) 535 & 735 ; A . B . Migdal

I. Ya. Pomeranchuk
Phys . Rev . • 2003


X. Bertou, P. Billoir, S. Dagoret-Campagne
Phys. 14 • 2000
View 1 Excerpt


P. Bhattacharjee, G. Sigl
Rep. 327 • 2000


T. J. Weiler
Rev. Lett. 49 (1982) 234; T.J. Weiler, Astropart. Phys. 11 (1999) 303; D. Fargion, B. Mele, A. Salis, Astrophys. J. 517 • 1999

in: Proc

R. Engel, T. K. Gaisser, P. Lipari, T. Stanev
26th Intern. Cosmic Ray Conf., Salt Lake City • 1999