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arXiv · 1105.1111

Disappointing model for ultrahigh-energy cosmic rays

R. Aloisio·V. Berezinsky·A. Gazizov
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Abstract

Data of Pierre Auger Observatory show a proton-dominated chemical composition of ultrahigh-energy cosmic rays spectrum at (1 - 3) EeV and a steadily heavier composition with energy increasing. In order to explain this feature we assume that (1 - 3) EeV protons are extragalactic and derive their maximum acceleration energy, E_p^{max} \simeq 4 EeV, compatible with both the spectrum and the composition. We also assume the rigidity-dependent acceleration mechanism of heavier nuclei, E_A^{max} = Z x E_p^{max}. The proposed model has rather disappointing consequences: i) no pion photo-production on CMB photons in extragalactic space and hence ii) no high-energy cosmogenic neutrino fluxes; iii) no GZK-cutoff in the spectrum; iv) no correlation with nearby sources due to nuclei deflection in the galactic magnetic fields up to highest energies.

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R. Aloisio, V. Berezinsky, A. Gazizov. 2011-05-05. Disappointing model for ultrahigh-energy cosmic rays. https://doi.org/10.1088/1742-6596/337/1/012042

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