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Title: Neutrino diagnostics of ultrahigh energy cosmic ray protons

Abstract

The energy at which cosmic rays from extra-galactic sources begin to dominate over those from galactic sources is an important open question in astroparticle physics. A natural candidate is the energy at the 'ankle' in the approximately power-law energy spectrum which is indicative of a crossover from a falling galactic component to a flatter extra-galactic component. The transition can occur without such flattening but this requires some degree of conspiracy of the spectral shapes and normalizations of the two components. Nevertheless, it has been argued that extra-galactic sources of cosmic ray protons that undergo interactions on the CMB can reproduce the energy spectrum below the ankle if the crossover energy is as low as the 'second knee' in the spectrum. This low crossover model is constrained by direct measurements by the Pierre Auger Observatory, which indicate a heavier composition at these energies. We demonstrate that upper limits on the cosmic diffuse neutrino flux provide a complementary constraint on the proton fraction in ultra-high energy extra-galactic cosmic rays and forthcoming data from IceCube will provide a definitive test of this model.

Authors:
;  [1];  [2]
  1. Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom)
  2. Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States)
Publication Date:
OSTI Identifier:
21308252
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 79; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.79.083009; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC RADIATION; ENERGY SPECTRA; GALAXIES; INTERACTIONS; NEUTRINOS; PROTONS; RELICT RADIATION; SIMULATION

Citation Formats

Ahlers, Markus, Sarkar, Subir, and Anchordoqui, Luis A. Neutrino diagnostics of ultrahigh energy cosmic ray protons. United States: N. p., 2009. Web. doi:10.1103/PHYSREVD.79.083009.
Ahlers, Markus, Sarkar, Subir, & Anchordoqui, Luis A. Neutrino diagnostics of ultrahigh energy cosmic ray protons. United States. https://doi.org/10.1103/PHYSREVD.79.083009
Ahlers, Markus, Sarkar, Subir, and Anchordoqui, Luis A. Wed . "Neutrino diagnostics of ultrahigh energy cosmic ray protons". United States. https://doi.org/10.1103/PHYSREVD.79.083009.
@article{osti_21308252,
title = {Neutrino diagnostics of ultrahigh energy cosmic ray protons},
author = {Ahlers, Markus and Sarkar, Subir and Anchordoqui, Luis A},
abstractNote = {The energy at which cosmic rays from extra-galactic sources begin to dominate over those from galactic sources is an important open question in astroparticle physics. A natural candidate is the energy at the 'ankle' in the approximately power-law energy spectrum which is indicative of a crossover from a falling galactic component to a flatter extra-galactic component. The transition can occur without such flattening but this requires some degree of conspiracy of the spectral shapes and normalizations of the two components. Nevertheless, it has been argued that extra-galactic sources of cosmic ray protons that undergo interactions on the CMB can reproduce the energy spectrum below the ankle if the crossover energy is as low as the 'second knee' in the spectrum. This low crossover model is constrained by direct measurements by the Pierre Auger Observatory, which indicate a heavier composition at these energies. We demonstrate that upper limits on the cosmic diffuse neutrino flux provide a complementary constraint on the proton fraction in ultra-high energy extra-galactic cosmic rays and forthcoming data from IceCube will provide a definitive test of this model.},
doi = {10.1103/PHYSREVD.79.083009},
url = {https://www.osti.gov/biblio/21308252}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 8,
volume = 79,
place = {United States},
year = {2009},
month = {4}
}