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arXiv · 2102.07797

Measurement of the fluctuations in the number of muons in extensive air showers with the Pierre Auger Observatory

The Pierre Auger Collaboration·A. Aab·P. Abreu·M. Aglietta·J. M. Albury·I. Allekotte·A. Almela·J. Alvarez-Muñiz·R. Alves Batista·G. A. Anastasi·L. Anchordoqui·B. Andrada·S. Andringa·C. Aramo·P. R. Araújo Ferreira·H. Asorey·P. Assis·G. Avila·A. M. Badescu·A. Bakalova·A. Balaceanu·F. Barbato·R. J. Barreira Luz·K. H. Becker·J. A. Bellido·C. Berat·M. E. Bertaina·X. Bertou·P. L. Biermann·T. Bister·J. Biteau·J. Blazek·C. Bleve·M. Boháčová·D. Boncioli·C. Bonifazi·L. Bonneau Arbeletche·N. Borodai·A. M. Botti·J. Brack·T. Bretz·F. L. Briechle·P. Buchholz·A. Bueno·S. Buitink·M. Buscemi·K. S. Caballero-Mora·L. Caccianiga·A. Cancio·F. Canfora·I. Caracas·J. M. Carceller·R. Caruso·A. Castellina·F. Catalani·G. Cataldi·L. Cazon·M. Cerda·J. A. Chinellato·K. Choi·J. Chudoba·L. Chytka·R. W. Clay·A. C. Cobos Cerutti·R. Colalillo·A. Coleman·M. R. Coluccia·R. Conceição·A. Condorelli·G. Consolati·F. Contreras·F. Convenga·C. E. Covault·S. Dasso·K. Daumiller·B. R. Dawson·J. A. Day·R. M. de Almeida·J. de Jesús·S. J. de Jong·G. De Mauro·J. R. T. de Mello Neto·I. De Mitri·J. de Oliveira·D. de Oliveira Franco·V. de Souza·E. De Vito·J. Debatin·M. del Río·O. Deligny·H. Dembinski·N. Dhital·A. Di Matteo·C. Dobrigkeit·J. C. D'Olivo·R. C. dos Anjos·M. T. Dova·J. Ebr·R. Engel·I. Epicoco
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Abstract

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.

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The Pierre Auger Collaboration, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, J. Alvarez-Muñiz, R. Alves Batista, G. A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, P. R. Araújo Ferreira, H. Asorey, P. Assis, G. Avila, A. M. Badescu, A. Bakalova, A. Balaceanu, F. Barbato, R. J. Barreira Luz, K. H. Becker, J. A. Bellido, C. Berat, M. E. Bertaina, X. Bertou, P. L. Biermann, T. Bister, J. Biteau, J. Blazek, C. Bleve, M. Boháčová, D. Boncioli, C. Bonifazi, L. Bonneau Arbeletche, N. Borodai, A. M. Botti, J. Brack, T. Bretz, F. L. Briechle, P. Buchholz, A. Bueno, S. Buitink, M. Buscemi, K. S. Caballero-Mora, L. Caccianiga, A. Cancio, F. Canfora, I. Caracas, J. M. Carceller, R. Caruso, A. Castellina, F. Catalani, G. Cataldi, L. Cazon, M. Cerda, J. A. Chinellato, K. Choi, J. Chudoba, L. Chytka, R. W. Clay, A. C. Cobos Cerutti, R. Colalillo, A. Coleman, M. R. Coluccia, R. Conceição, A. Condorelli, G. Consolati, F. Contreras, F. Convenga, C. E. Covault, S. Dasso, K. Daumiller, B. R. Dawson, J. A. Day, R. M. de Almeida, J. de Jesús, S. J. de Jong, G. De Mauro, J. R. T. de Mello Neto, I. De Mitri, J. de Oliveira, D. de Oliveira Franco, V. de Souza, E. De Vito, J. Debatin, M. del Río, O. Deligny, H. Dembinski, N. Dhital, A. Di Matteo, C. Dobrigkeit, J. C. D'Olivo, R. C. dos Anjos, M. T. Dova, J. Ebr, R. Engel, I. Epicoco. 2021-02-15. Measurement of the fluctuations in the number of muons in extensive air showers with the Pierre Auger Observatory. https://doi.org/10.1103/physrevlett.126.152002

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