Dip in UHECR spectrum as signature of proton interaction with CMB

By V. Berezinsky, A. Gazizov, S. Grigorieva. 2005

182 citations recorded by the source corpus.

Abstract Ultrahigh energy (UHE) extragalactic protons propagating through cosmic microwave radiation (CMB) acquire the spectrum features in the form of the dip, bump (pile-up protons) and the Greisen–Zatsepin–Kuzmin (GZK) cutoff. We have performed the analysis of these features in terms of the modification factor. This analysis is weakly model-dependent, especially in case of the dip. The energy shape of the dip is confirmed by the Akeno-AGASA data with χ 2 = 19.06 for d.o.f. = 17 with two free parameters used for comparison. The agreement with HiRes data is also very good. This is the strong evidence that UHE cosmic rays observed at energies 1 × 10 18 – 4 × 10 19 eV are extragalactic protons propagating through CMB. The dip is also present in case of diffusive propagation in magnetic field.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/b01dd844ced1c5a1ee8cb9fe58bc2e20c245ae8d

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Citations in the corpus

The Astrophysics of Ultrahigh-Energy Cosmic Rays (2011, background): “The dip model can fit the observed spectrum if the injection is proton dominated (Berezinsky et al. 2005; Allard et al. 2007) or with at most a primordial proton to helium mix (Hillas 2006), which gives a clear path for distinguishing it from mixed composition models.”
UHE nuclei propagation and the interpretation of the ankle in the cosmic-ray spectrum (2005, background): “Therefore, the interpretation of the ankle as an e+-e− pair production dip requires a very large fraction of protons at the source (see also Berezinsky et al., 2005).”
The Muon Puzzle in cosmic-ray induced air showers and its connection to the Large Hadron Collider (2021, background): “…are well-known to affect the cosmic-ray flux measured by different experiments, leading to shifts in the flux that are consistent within the uncertainties of the respective energy scales, see e.g. Hoerandel (2003), Berezinsky et al. (2006, 2005), Dembinski et al. (2018), AbuZayyad et al. (2019).”