Document Type
Article
Publication Date
8-1-2020
Department
Department of Physics
Abstract
The hybrid design of the Pierre Auger Observatory allows for the measurement of the properties of extensive air showers initiated by ultra-high energy cosmic rays with unprecedented precision. By using an array of prototype underground muon detectors, we have performed the first direct measurement, by the Auger Collaboration, of the muon content of air showers between 2 × 10 17 and 2 × 10 18 eV. We have studied the energy evolution of the attenuation-corrected muon density, and compared it to predictions from air shower simulations. The observed densities are found to be larger than those predicted by models. We quantify this discrepancy by combining the measurements from the muon detector with those from the Auger fluorescence detector at 1017.5eV and 1018eV. We find that, for the models to explain the data, an increase in the muon density of 38 % ± 4 % (12 %) ±18%21% for EPOS-LHC, and of 50 % (53 %) ± 4 % (13 %) ±20%23% for QGSJetII-04, is respectively needed.
Publication Title
European Physical Journal C
Recommended Citation
Aab, A.,
Abreu, P.,
Aglietta, M.,
Albury, J.,
Allekotte, I.,
Almela, A.,
Alvarez Castillo, J.,
Alvarez-Muñiz, J.,
Anastasi, G.,
Anchordoqui, L.,
Andrada, B.,
Andringa, S.,
Aramo, C.,
Araújo Ferreira, P.,
Asorey, H.,
Assis, P.,
Avila, G.,
Badescu, A.,
Bakalova, A.,
Balaceanu, A.,
Barbato, F.,
Barreira Luz, R.,
Becker, K.,
Bellido, J.,
Berat, C.,
Bertaina, M.,
Bertou, X.,
Biermann, P.,
Bister, T.,
Biteau, J.,
Blanco, A.,
Blazek, J.,
Fick, B.,
Nitz, D. F.,
&
Puyleart, A.
(2020).
Direct measurement of the muonic content of extensive air showers between 2× 1017 and 2×1018 eV at the Pierre Auger Observatory.
European Physical Journal C,
80(8).
http://doi.org/10.1140/epjc/s10052-020-8055-y
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/2674
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
© 2020, The Author(s). Publisher’s version of record: https://doi.org/10.1140/epjc/s10052-020-8055-y