RT Journal Article T1 Search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory A1 Arqueros Martínez, Fernando A1 García Pinto, Diego A1 Minaya Flores, Ignacio Andrés A1 Vázquez Peñas, José Ramón AB We present a search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory. Such particles, possibly a relic of phase transitions in the early Universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air-shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultrarelativistic magnetic monopoles range from 10(-1)9 (cm(2) sr s)(-1) for a Lorentz factor gamma = 10(9) to 2.5 x 10(-21) (cm(2) sr s)(-1) for gamma = 10(12). These results-the first obtained with a UHECR detector-improve previously published limits by up to an order of magnitude. PB Amer Physical Soc SN 2470-0010 YR 2016 FD 2016-10-03 LK https://hdl.handle.net/20.500.14352/17570 UL https://hdl.handle.net/20.500.14352/17570 LA eng NO © Amer Physical Soc 2016.Autoría conjunta: Pierre Auger Collaboration. Artículo firmado por más de 10 autores.The successful installation, commissioning, and operation of the Pierre Auger observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargue. We are very grateful to the following agencies and organizations for financial support: Comision Nacional de Energia Atomica, Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), and Gobierno de la Provincia de Mendoza, Municipalidad de Malargue, NDM Holdings and Valle Las Lenas, Argentina, in gratitude for their continuing cooperation over land access; the Australian Research Council; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundacao de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ), Sao Paulo Research Foundation (FAPESP) Grants No. 2010/07359-6 and No. 1999/05404-3, Ministerio de Ciencia e Tecnologia (MCT), Brazil, Grants No. MSMT CR LG15014, No. LO1305 and No. LM2015038 and the Czech Science Foundation Grant No. 14-17501S, Czech Republic; Centre de Calcul IN2P3/CNRS, Centre National de la Recherche Scientifique (CNRS), Conseil Regional Ile-de-France, Departement Physique Nucleaire et Corpusculaire (PNC-IN2P3/CNRS), Departement Sciences de l'Univers (SDU-INSU/CNRS), and Institut Lagrange de Paris (ILP) Grant No. LABEX ANR-10-LABX-63, within the Investissements d'Avenir Programme Grant No. ANR-11-IDEX-0004-02, France; Bundesministerium fur Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Finanzministerium Baden-Wurttemberg, Helmholtz Alliance for Astroparticle Physics (HAP), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF), Ministerium fur Wissenschaft und Forschung, Nordrhein Westfalen, Ministerium fur Wissenschaft, Forschung und Kunst, Baden-Wurttemberg, Germany; Istituto Nazionale di Fisica Nucleare (INFN), Istituto Nazionale di Astrofisica (INAF), Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR), Gran Sasso Center for Astroparticle Physics (CFA), CETEMPS Center of Excellence, and Ministero degli Affari Esteri (MAE), Italy; Consejo Nacional de Ciencia y Tecnología (CONACYT) Grant No. 167733, Mexico; Universidad Nacional Autónoma de México (UNAM), PAPIIT DGAPA-UNAM, Mexico; Ministerie van Onderwijs, Cultuur en Wetenschap, Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), and Stichting voor Fundamenteel Onderzoek der Materie (FOM), Netherlands; National Centre for Research and Development, Grants No. ERANET-ASPERA/01/11 and No. ERA-NET-ASPERA/02/11, and National Science Centre, Grants No. 2013/08/M/ST9/00322, No. 2013/08/M/ST9/00728 and No. HARMONIA 5–2013/10/M/ST9/00062, Poland; Portuguese national funds and FEDER funds within Programa Operacional Factores de Competitividade through Fundação para a Ciência e a Tecnologia (COMPETE), Portugal; Romanian Authority for Scientific Research ANCS, CNDI-UEFISCDI partnership projects Grants No. 20/2012, No. 194/2012 and No. PN 16 42 01 02; Slovenian Research Agency, Slovenia; Comunidad de Madrid, Fondo Europeo de Desarrollo Regional (FEDER) funds, Ministerio de Economía y Competitividad, Xunta de Galicia, and European Community 7th Framework Program, Grant No. FP7-PEOPLE-2012-IEF-328826, Spain; Science and Technology Facilities Council, United Kingdom; Department of Energy Awards No. DE-AC02-07CH11359, No. DE-FR02-04ER41300, No. DE-FG02-99ER41107 and No. DE-SC0011689, National Science Foundation, Grant No. 0450696, and The Grainger Foundation, USA; NAFOSTED, Vietnam; Marie CurieIRSES/EPLANET, European Particle Physics Latin American Network, European Union 7th Framework Program, Grant No. PIRSES-2009-GA-246806; and UNESCO. This work was supported in part by NSF Grant No. PHY-1412261 and by the Kavli Institute for Cosmological Physics at the University of Chicago through Grant No. NSF PHY-1125897 and an endowment from the Kavli Foundation and its founder Fred Kavli. T. F. was supported by the Japan Society for the Promotion of Science Fellowship for Research Abroad Grant No. H25-339. NO Unión Europea. FP7 NO Ministerio de Economía y Competitividad (MINECO) NO Czech Science Foundation, Czech Republic NO Centre de Calcul IN2P3/CNRS, France NO Centre National de la Recherche Scientifique (CNRS), France NO Conseil Regional Ile-de-France, France NO Departement Physique Nucleaire et Corpusculaire (PNC-IN2P3/CNRS), France NO Departement Sciences de l'Univers (SDU-INSU/CNRS), France NO Institut Lagrange de Paris (ILP) Grant, within the Investissements d'Avenir Programme Grant, France NO Bundesministerium fur Bildung und Forschung (BMBF) NO Deutsche Forschungsgemeinschaft (DFG) NO Finanzministerium Baden-Wurttemberg NO Helmholtz Alliance for Astroparticle Physics (HAP) NO Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF) NO Ministerium fur Wissenschaft und Forschung, Nordrhein Westfalen NO Ministerium fur Wissenschaft, Forschung und Kunst, Baden-Wurttemberg, Germany NO Istituto Nazionale di Fisica Nucleare (INFN) NO Istituto Nazionale di Astrofisica (INAF) NO Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR) NO Gran Sasso Center for Astroparticle Physics (CFA) NO CETEMPS Center of Excellence NO Ministero degli Affari Esteri (MAE), Italy NO Ministerie van Onderwijs, Cultuur en Wetenschap NO Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) NO Stichting voor Fundamenteel Onderzoek der Materie (FOM), Netherlands NO National Centre for Research and Development NO National Science Centre, Poland NO Portuguese national funds NO FEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE), Portugal NO Romanian Authority for Scientific Research ANCS, CNDI-UEFISCDI partnership projects NO Slovenian Research Agency, Slovenia NO Comunidad de Madrid, Fondo Europeo de Desarrollo Regional (FEDER) funds NO UNESCO NO Xunta de Galicia NO Science and Technology Facilities Council, United Kingdom NO Department of Energy NO National Science Foundation DS Docta Complutense RD 9 jun 2025