Observation of the suppression of the flux of cosmic rays above 4×1019eV
Document Type
Article
Publication Date
8-4-2008
Abstract
The energy spectrum of cosmic rays above 2.5×1018eV, derived from 20000 events recorded at the Pierre Auger Observatory, is described. The spectral index γ of the particle flux, JE-γ, at energies between 4×1018eV and 4×1019eV is 2.69±0.02(stat)±0.06(syst), steepening to 4.2±0.4(stat)±0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min. © 2008 The American Physical Society.
Publication Title
Physical Review Letters
Recommended Citation
Abraham, J.,
Abreu, P.,
Aglietta, M.,
Aguirre, C.,
Allard, D.,
Allekotte, I.,
Allen, J.,
Allison, P.,
Alvarez-Muñiz, J.,
Ambrosio, M.,
Anchordoqui, L.,
Andringa, S.,
Anzalone, A.,
Aramo, C.,
Argirò, S.,
Arisaka, K.,
Armengaud, E.,
Arneodo, F.,
Arqueros, F.,
Asch, T.,
Asorey, H.,
Assis, P.,
Atulugama, B.,
Aublin, J.,
Ave, M.,
Avila, G.,
Bäcker, T.,
Badagnani, D.,
Barbosa, A.,
Barnhill, D.,
Barroso, S.,
&
Baughman, B.
(2008).
Observation of the suppression of the flux of cosmic rays above 4×1019eV.
Physical Review Letters,
101(6).
http://doi.org/10.1103/PhysRevLett.101.061101
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/10085