Origin of the ankle in the ultrahigh energy cosmic ray spectrum, and of the extragalactic protons below it

Michael Unger, Glennys R. Farrar, Luis A. Anchordoqui

    Research output: Contribution to journalArticle

    Abstract

    The sharp change in slope of the ultrahigh energy cosmic ray (UHECR) spectrum around 1018.6 eV (the ankle), combined with evidence of a light but extragalactic component near and below the ankle and intermediate composition above, has proved exceedingly challenging to understand theoretically, without fine-tuning. We propose a mechanism whereby photo-disintegration of ultrahigh energy nuclei in the region surrounding a UHECR accelerator accounts for the observed spectrum and inferred composition at Earth. For suitable source conditions, the model reproduces the spectrum and the composition over the entire extragalactic cosmic ray energy range, i.e. above 1017.5 eV. Predictions for the spectrum and flavors of neutrinos resulting from this process are also presented.

    Original languageEnglish (US)
    Article number123001
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Volume92
    Issue number12
    DOIs
    StatePublished - Dec 1 2015

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    cosmic rays
    protons
    extraterrestrial radiation
    energy
    disintegration
    accelerators
    neutrinos
    tuning
    slopes
    nuclei
    predictions

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics

    Cite this

    Origin of the ankle in the ultrahigh energy cosmic ray spectrum, and of the extragalactic protons below it. / Unger, Michael; Farrar, Glennys R.; Anchordoqui, Luis A.

    In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 92, No. 12, 123001, 01.12.2015.

    Research output: Contribution to journalArticle

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