Upper limit on the cosmic-ray photon fraction at EeV energies from the Pierre Auger Observatory

Abraham, J.; Pepe, Iuri Muniz; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E. J.

dc.contributor.author	Abraham, J.
dc.contributor.author	Pepe, Iuri Muniz
dc.contributor.author	Abreu, P.
dc.contributor.author	Aglietta, M.
dc.contributor.author	Aguirre, C.
dc.contributor.author	Ahn, E. J.
dc.creator	Abraham, J.
dc.creator	Pepe, Iuri Muniz
dc.creator	Abreu, P.
dc.creator	Aglietta, M.
dc.creator	Aguirre, C.
dc.creator	Ahn, E. J.
dc.date.accessioned	2013-11-19T20:24:56Z
dc.date.issued	2009
dc.identifier.issn	0927-6505
dc.identifier.uri	http://repositorio.ufba.br/ri/handle/ri/13777
dc.description	Texto completo: acesso restrito. p. 399–406	pt_BR
dc.description.abstract	From direct observations of the longitudinal development of ultra-high energy air showers performed with the Pierre Auger Observatory, upper limits of 3.8%, 2.4%, 3.5% and 11.7% (at 95% c.l.) are obtained on the fraction of cosmic-ray photons above 2, 3, 5 and 10 EeV View the MathML source, respectively. These are the first experimental limits on ultra-high energy photons at energies below 10 EeV. The results complement previous constraints on top–down models from array data and they reduce systematic uncertainties in the interpretation of shower data in terms of primary flux, nuclear composition and proton-air cross-section.	pt_BR
dc.language.iso	en	pt_BR
dc.rights	Acesso Aberto	pt_BR
dc.source	http://dx.doi.org/10.1016/j.astropartphys.2009.04.003	pt_BR
dc.title	Upper limit on the cosmic-ray photon fraction at EeV energies from the Pierre Auger Observatory	pt_BR
dc.title.alternative	Astroparticle Physics	pt_BR
dc.type	Artigo de Periódico	pt_BR
dc.identifier.number	v. 31, n. 6	pt_BR
dc.embargo.liftdate	10000-01-01