Autor(es):
Müller, Márcio Aparecido, 1975- ; Nogima, Hélio, 1963- ; Prado Junior, Luís, 1969- ; Peixoto, Carlos José Todero, 1974-
Data: 2007
Identificador Persistente: https://hdl.handle.net/20.500.12733/1666237
Origem: Oasisbr
Assunto(s): Raios cósmicos; Chuveiros de raios cósmicos; Detectores; Observatório Pierre Auger; Pierre Auger Observatory; Cosmic rays; Cosmic ray showers; Detectors; Ultra-high energy photons; Extensive air showers; Artigo original; Raios cósmicos; Raios cósmicos; Chuveiros de raios cósmicos; Chuveiros de raios cósmicos; Detectores; Detectores; Observatório Pierre Auger; Observatório Pierre Auger; Pierre Auger Observatory; Pierre Auger Observatory; Cosmic rays; Cosmic rays; Cosmic ray showers; Cosmic ray showers; Detectors; Detectors; Ultra-high energy photons; Ultra-high energy photons; Extensive air showers; Extensive air showers; Artigo original; Artigo original
Descrição
Agradecimentos: We are very grateful to the following agencies and organisations for financial support: Gobierno de Mendoza, Comisión Nacional de Energia Atómica y Municipalidad de Malargüe, Argentina; the Australian Research Council; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and Fundacao de Amparo a Pesquisa do Estado de Rio de Janeiro, Brasil; National Science Foundation of China; Ministry of Education of the Czech Republic (projects LA134 and LN00A006); Centre National de la Recherche Scientifique, Institut National de Physique Nucléaire et Physique des Particules (IN2P3/CNRS), Institut National des Sciences de l’Univers (INSU/CNRS) et Conseil Régional Ile de France, France; German Ministry for Education and Research and Forschungszentrum Karlsruhe, Germany; Istituto Nazionale di Fisica Nucleare, Italy; Consejo Nacional de Ciencia y Tecnologia, Mexico; the Polish State Committee for Scientific Research (grant numbers 1P03D 01430, 2P03B 11024 and 2PO3D 01124), Poland; Slovenian Research Agency; Ministerio de Educación y Ciencia (FPA2003-08733-C02, 2004-01198), Xunta de Galicia (2003 PXIC20612PN, 2005 PXIC20604PN) and Feder Funds, Spain; Particle Physics and Astronomy Research Council, UK; the US Department of Energy, the US National Science Foundation, USA, and UNESCO. Partial support of ALFA-EC funds, in the framework of the HELEN Project, is gratefully acknowledged
Abstract: An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies greater than 10(19) 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 surface detectors for a subset of the event sample support the conclusion that a photon origin of the observed events is not favored
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ
FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJ
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