Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (Xmax), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the distributions with predictions from a variety of hadronic interaction models for variations in the composition of the primary cosmic rays and examining the quality of the fit. Regardless of what interaction model is assumed, we find that our data are not well described by a mix of protons and iron nuclei over most of the energy range. Acceptable fits can be obtained when intermediate masses are included, and when this is done consistent results for the proton and iron-nuclei contributions can be found using the available models. We observe a strong energy dependence of the resulting proton fractions, and find no support from any of the models for a significant contribution from iron nuclei. However, we also observe a significant disagreement between the models with respect to the relative contributions of the intermediate components. © 2014 American Physical Society.
Documento: | Artículo |
Título: | Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications |
Autor: | Multitudinario:485 |
Filiación: | Universität Siegen, Siegen, Germany Laboratório de Instrumentação e Física Experimental de Partículas, Instituto Superior Técnico (IST), Universidade de Lisboa (UL), Portugal Osservatorio Astrofisico di Torino (INAF), Università di Torino, Sezione INFN, Torino, Italy Fermilab, Batavia, IL, United States Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris 11, CNRS-IN2P3, Orsay, France Universidade de São Paulo, Instituto de Física, São Paulo, São Paulo, Brazil Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche, Argentina New York University, New York, NY, United States Ohio State University, Columbus, OH, United States Universidad Tecnológica Nacional-Facultad Regional Buenos Aires, Buenos Aires, Argentina Instituto de Tecnologías en Detección y Astropartículas (CNEA CONICET, UNSAM), Buenos Aires, Argentina Universidad Nacional Autonoma de Mexico, Mexico, Distrito Federal, Mexico Universidad de Santiago de Compostela, Spain Universität Hamburg, Hamburg, Germany Università di Napoli Federico II, Sezione INFN, Napoli, Italy IMAPP, Radboud University, Nijmegen, Netherlands Department of Physics and Astronomy, Lehman College, City University of New York, New York, United States Universidad Complutense de Madrid, Madrid, Spain Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3, Paris, France Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Grenoble-Alpes, CNRS/IN2P3, France Observatorio Pierre Auger and Comisión Nacional de Energía Atómica, Malargüe, Argentina University Politehnica of Bucharest, Romania University of Adelaide, Adelaide, SA, Australia Karlsruhe Institute of Technology, Campus South, Institut für Experimentelle Kernphysik (IEKP), Karlsruhe, Germany Bergische Universität Wuppertal, Wuppertal, Germany Max-Planck-Institut für Radioastronomie, Bonn, Germany Dipartimento di Matematica e Fisica E. de Giorgi, Università Del Salento, Sezione INFN, Lecce, Italy Karlsruhe Institute of Technology, Campus North, Institut für Kernphysik, Karlsruhe, Germany Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic INFN, Laboratori Nazionali Del Gran Sasso, Assergi (l'Aquila), Italy Universidade Federal Do Rio de Janeiro, Instituto de Física, Rio de Janeiro, Rio de Janeiro, Brazil Institute of Nuclear Physics PAN, Krakow, Poland Colorado State University, Fort Collins, CO, United States 'Horia Hulubei' National Institute for Physics and Nuclear Engineering, Bucharest-Magurele, Romania Colorado State University, Pueblo, CO, United States Universidad de Granada and C.A.F.P.E., Granada, Spain Centro de Investigación y de Estudios Avanzados Del IPN (CINVESTAV), México, Distrito Federal, Mexico Università di Milano, Sezione INFN, Milan, Italy Università di Roma II Tor Vergata, Sezione INFN, Roma, Italy Università di Catania, Sezione INFN, Catania, Italy Università di Torino, Sezione INFN, Torino, Italy Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan, Mexico Universidade Estadual de Campinas, IFGW, Campinas, São Paulo, Brazil Pennsylvania State University, University Park, United States Observatorio Pierre Auger, Malargüe, Argentina Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris 11, CNRS-IN2P3, Orsay, France Case Western Reserve University, Cleveland, OH, United States University of Chicago, Enrico Fermi Institute, Chicago, IL, United States SUBATECH, École des Mines de Nantes, Université de Nantes, Nantes, France Station de Radioastronomie de Nançay, Observatoire de Paris, CNRS/INSU, Nançay, France Instituto de Astronomía y Física Del Espacio (CONICET-UBA), Buenos Aires, Argentina Departamento de Física, FCEyN, Universidad de Buenos Aires y CONICET, Argentina Universidade Federal Fluminense, EEIMVR, Volta Redonda, Rio de Janeiro, Brazil Nikhef, Science Park, Amsterdam, Netherlands Universidade de São Paulo, Instituto de Física de São Carlos, São Carlos, São Paulo, Brazil Universidad de Alcalá, Alcalá de Henares, Spain Michigan Technological University, Houghton, MI, United States Dipartimento di Scienze Fisiche e Chimiche, Università dell'Aquila, INFN, Italy KVI, Center for Advanced Radiation Technology, University of Groningen, Groningen, Netherlands IFLP, Universidad Nacional de la Plata, CONICET, La Plata, Argentina RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany ASTRON, Dwingeloo, Netherlands Experimental Particle Physics Department, J. Stefan Institute, Ljubljana, Slovenia Laboratory for Astroparticle Physics, University of Nova Gorica, Slovenia University of Hawaii, Honolulu, HI, United States Instituto de Tecnologías en Detección y Astropartículas (CNEA CONICET, UNSAM), National Technological University, Faculty Mendoza (CONICET/CNEA), Mendoza, Argentina Karlsruhe Institute of Technology, Campus North, Institut für Prozessdatenverarbeitung und Elektronik, Germany University of Łódź, Łódź, Poland Universidade Estadual de Feira de Santana, Brazil Palacky University, RCPTM, Olomouc, Czech Republic Institute of Space Sciences, Bucharest, Romania University of New Mexico, Albuquerque, NM, United States Faculdade Independente Do Nordeste, Vitória da Conquista, Brazil Universidade Federal Do ABC, Santo André, São Paulo, Brazil Benemérita Universidad Autónoma de Puebla, Mexico School of Physics and Astronomy, University of Leeds, United Kingdom Louisiana State University, Baton Rouge, LA, United States Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Rio de Janeiro, Brazil Colorado School of Mines, Golden, CO, United States Rudjer Bošković Institute, Zagreb, 10000, Croatia Instituto de Física de Rosario (IFIR), CONICET/U.N.R., Facultad de Ciencias Bioquímicas y Farmacéuticas U.N.R., Rosario, Argentina Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, Brazil Charles University, Faculty of Mathematics and Physics, Institute of Particle and Nuclear Physics, Prague, Czech Republic Centro de Investigaciones en Láseres y Aplicaciones, CITEDEF and CONICET, Argentina Northeastern University, Boston, MA, United States Universidade Federal da Bahia, Salvador, Bahia, Brazil University of Nebraska, Lincoln, NE, United States Gran Sasso Science Institute (INFN), L'Aquila, Italy Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo (INAF), Palermo, Italy University of Bucharest, Physics Department, Romania Universidade de São Paulo, Escola de Engenharia de Lorena, Lorena, São Paulo, Brazil |
Año: | 2014 |
Volumen: | 90 |
Número: | 12 |
DOI: | http://dx.doi.org/10.1103/PhysRevD.90.122006 |
Título revista: | Physical Review D - Particles, Fields, Gravitation and Cosmology |
Título revista abreviado: | Phys Rev D Part Fields Gravit Cosmol |
ISSN: | 15507998 |
CODEN: | PRVDA |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15507998_v90_n12_p_Multitudinario |