Has the GZK cutoff been discovered?
We show that the combined observational data from the Fly's Eye, HiRes, and Yakutsk cosmic ray experiments strongly suggest (~ 7 sigma) that the Greisen-Zatsepin-Kuzmin (GZK) cutoff is present in the observed energy spectrum of ultra-high-energy cosmic rays. However, Top-Down models which invok...
Main Authors: | , |
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Language: | English |
Published: |
2002
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Subjects: | |
Online Access: | http://cds.cern.ch/record/563893 |
Summary: | We show that the combined observational data from the Fly's Eye, HiRes, and Yakutsk cosmic ray experiments strongly suggest (~ 7 sigma) that the Greisen-Zatsepin-Kuzmin (GZK) cutoff is present in the observed energy spectrum of ultra-high-energy cosmic rays. However, Top-Down models which invoke decaying heavy particles are consistent with the AGASA cosmic ray data. High statistics measurements in the cosmic ray energy range between 10^{18} eV to 5*10^{19} eV will be necessary to test for the characteristic differences between Top-Down models and more conventional models. |
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