2013/06/30 by Luis A. Anchordoqui, Haim Goldberg, Morgan H. Lynch +4 · 3 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #COSMIC cancer database #Cosmic ray #Dark Matter and Cosmic Phenomena #Mechanism (biology) #Physics #Radio Astronomy Observations and Technology #astro-ph.HE #hep-ph
paper · pdf · doi:10.1103/physrevd.89.083003
Matching version to be published in Physical Review D
arxiv created 2014/03/25 · openalex publication_date 2014/04/04 · arxiv updated 2015/06/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Very recently the IceCube Collaboration has reported an observation of 28 neutrino candidates with energies between 50 TeV and 2 PeV, constituting a 4.1\ensuremathσ excess compared to the atmospheric background. In this article we investigate the compatibility between the data and a hypothesized unbroken power-law neutrino spectrum for various values of spectral index \mathrm\ensuremathΓ\ensuremath≥2. We show that \mathrm\ensuremathΓ\ensuremath∼2.3 is consistent at the \ensuremath∼1.5\ensuremathσ level with the observed events up to 2 PeV and to the null observation of events at higher energies. We then assume that the sources of this unbroken spectrum are Galactic, and deduce (i) an energy-transfer fraction from parent protons to pions (finding \ensuremathε_\ensuremathπ^\ifmmode±\else\textpm\fi and \ensuremathε_\ensuremathπ), and (ii) a way of discriminating among models which have been put forth to explain the ``knee'' and ``ankle'' features of the cosmic ray spectrum. Future IceCube data will test the unbroken power-law hypothesis and provide a multimessenger approach to explaining features of the cosmic ray spectrum, including the transition from Galactic to extragalactic dominance.