Authors
A Aab, P Abreu, MARCO Aglietta, EJ Ahn, I Al Samarai, IFM Albuquerque, Ingomar Allekotte, J Allen, P Allison, A Almela, J Alvarez Castillo, J Alvarez-Muñiz, R Alves Batista, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, C Aramo, VM Aranda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, N Awal, AM Badescu, KB Barber, J Bäuml, C Baus, JJ Beatty, KH Becker, JA Bellido, C Berat, ME Bertania, X Bertou, PL Biermann, P Billoir, S Blaess, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, Raffaella Bonino, N Borodai, J Brack, I Brancus, A Bridgeman, P Brogueira, WC Brown, P Buchholz, A Bueno, S Buitink, M Buscemi, KS Caballero-Mora, B Caccianiga, L Caccianiga, M Candusso, L Caramete, R Caruso, ANTONELLA Castellina, G Cataldi, L Cazon, Rosanna Cester, AG Chavez, Andrea Chiavassa, JA Chinellato, J Chudoba, M Cilmo, RW Clay, G Cocciolo, R Colalillo, A Coleman, L Collica, MR Coluccia, R Conceicao, F Contreras, MJ Cooper, A Cordier, S Coutu, CE Covault, J Cronin, A Curutiu, R Dallier, B Daniel, S Dasso, K Daumiller, BR Dawson, RM De Almeida, M De Domenico, SJ De Jong, JRT de Mello Neto, I De Mitri, J De Oliveira, V De Souza, L Del Peral, O Deligny, H Dembinski, N Dhital, C Di Giulio, A Di Matteo, JC Diaz, ML Diaz Castro, F Diogo, C Dobrigkeit, W Docters, JC D’Olivo, A Dorofeev, Q Dorosti Hasankiadeh, MT Dova, J Ebr, R Engel, M Erdmann, M Erfani, CO Escobar, J Espadanal, A Etchegoyen, P Facal San Luis, H Falcke, K Fang, G Farrar, AC Fauth, N Fazzini, AP Ferguson, M Fernandes, B Fick, JM Figueira, A Filevich, A Filipčič, BD Fox, O Fratu, U Fröhlich, B Fuchs, T Fuji, R Gaior, B García, ST Garcia Roca, D Garcia-Gamez, D Garcia-Pinto, G Garilli, A Gascon Bravo, F Gate, H Gemmeke, PL Ghia, U Giaccari, M Giammarchi, M Giller
Publication date
2014/12/15
Journal
Physical Review D
Volume
90
Issue
12
Pages
122006
Publisher
American Physical Society
Description
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 (), 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 …
Scholar articles
A Aab, P Abreu, M Aglietta, EJ Ahn, I Al Samarai… - Physical Review D, 2014