Ultra-high energy cosmic rays and new physics
Cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin `cutoff' at $\sim 4 \times 10^{10}$ GeV pose a conundrum, the solution of which requires either drastic revision of our astrophysical understanding, or new physics beyond the Standard Model. Nucleons of such energies must originate wi...
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ftdatacite:10.48550/arxiv.hep-ph/0202013 2023-05-15T18:07:41+02:00 Ultra-high energy cosmic rays and new physics Sarkar, Subir 2002 https://dx.doi.org/10.48550/arxiv.hep-ph/0202013 https://arxiv.org/abs/hep-ph/0202013 unknown arXiv Assumed arXiv.org perpetual, non-exclusive license to distribute this article for submissions made before January 2004 http://arxiv.org/licenses/assumed-1991-2003/ High Energy Physics - Phenomenology hep-ph Astrophysics astro-ph FOS Physical sciences Preprint Article article CreativeWork 2002 ftdatacite https://doi.org/10.48550/arxiv.hep-ph/0202013 2022-04-01T16:40:22Z Cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin `cutoff' at $\sim 4 \times 10^{10}$ GeV pose a conundrum, the solution of which requires either drastic revision of our astrophysical understanding, or new physics beyond the Standard Model. Nucleons of such energies must originate within the local supercluster in order to avoid excessive energy losses through photopion production on the cosmic microwave background. However they do not point back towards possible nearby sources, e.g. the active galaxy Cen A or M87 in the Virgo cluster, so such an astrophysical origin requires intergalactic magnetic fields to be a hundred times stronger than previously believed, in order to isotropise their arrival directions. Alternatively the primaries may be high energy neutrinos, say from distant gamma-ray bursts, which annihilate on the local relic background neutrinos to create ``Z-bursts''. A related possibility is that the primary neutinos may initiate the observed air showers directly if their interaction cross-sections are boosted to hadronic strength through non-perturbative physics such as TeV-scale quantum gravity. Or the primaries may instead be new strongly interacting neutral particles with a longer mean free path than nucleons, coming perhaps from distant BL-Lac objects or FR-II radio galaxies. Yet another possibility is that Lorentz invariance is violated at high energies thus suppressing the energy loss processes altogether. The idea that has perhaps been studied in most detail is that such cosmic rays originate from the decays of massive relic particles (``wimpzillas'') clustered as dark matter in the galactic halo. All these hypotheses will soon be critically tested by the Pierre Auger Observatory, presently under construction in Argentina, and by proposed satellite experiments such as EUSO. : 15 pages (LaTeX), 6 figures; Invited talk at COSMO-01 Workshop, Rovaniemi, Finland, August 30-September 4, 2001; Changes: typos fixed, references added Report Rovaniemi DataCite Metadata Store (German National Library of Science and Technology) Argentina Rovaniemi ENVELOPE(26.159,26.159,66.392,66.392) |
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DataCite Metadata Store (German National Library of Science and Technology) |
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High Energy Physics - Phenomenology hep-ph Astrophysics astro-ph FOS Physical sciences |
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High Energy Physics - Phenomenology hep-ph Astrophysics astro-ph FOS Physical sciences Sarkar, Subir Ultra-high energy cosmic rays and new physics |
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High Energy Physics - Phenomenology hep-ph Astrophysics astro-ph FOS Physical sciences |
description |
Cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin `cutoff' at $\sim 4 \times 10^{10}$ GeV pose a conundrum, the solution of which requires either drastic revision of our astrophysical understanding, or new physics beyond the Standard Model. Nucleons of such energies must originate within the local supercluster in order to avoid excessive energy losses through photopion production on the cosmic microwave background. However they do not point back towards possible nearby sources, e.g. the active galaxy Cen A or M87 in the Virgo cluster, so such an astrophysical origin requires intergalactic magnetic fields to be a hundred times stronger than previously believed, in order to isotropise their arrival directions. Alternatively the primaries may be high energy neutrinos, say from distant gamma-ray bursts, which annihilate on the local relic background neutrinos to create ``Z-bursts''. A related possibility is that the primary neutinos may initiate the observed air showers directly if their interaction cross-sections are boosted to hadronic strength through non-perturbative physics such as TeV-scale quantum gravity. Or the primaries may instead be new strongly interacting neutral particles with a longer mean free path than nucleons, coming perhaps from distant BL-Lac objects or FR-II radio galaxies. Yet another possibility is that Lorentz invariance is violated at high energies thus suppressing the energy loss processes altogether. The idea that has perhaps been studied in most detail is that such cosmic rays originate from the decays of massive relic particles (``wimpzillas'') clustered as dark matter in the galactic halo. All these hypotheses will soon be critically tested by the Pierre Auger Observatory, presently under construction in Argentina, and by proposed satellite experiments such as EUSO. : 15 pages (LaTeX), 6 figures; Invited talk at COSMO-01 Workshop, Rovaniemi, Finland, August 30-September 4, 2001; Changes: typos fixed, references added |
format |
Report |
author |
Sarkar, Subir |
author_facet |
Sarkar, Subir |
author_sort |
Sarkar, Subir |
title |
Ultra-high energy cosmic rays and new physics |
title_short |
Ultra-high energy cosmic rays and new physics |
title_full |
Ultra-high energy cosmic rays and new physics |
title_fullStr |
Ultra-high energy cosmic rays and new physics |
title_full_unstemmed |
Ultra-high energy cosmic rays and new physics |
title_sort |
ultra-high energy cosmic rays and new physics |
publisher |
arXiv |
publishDate |
2002 |
url |
https://dx.doi.org/10.48550/arxiv.hep-ph/0202013 https://arxiv.org/abs/hep-ph/0202013 |
long_lat |
ENVELOPE(26.159,26.159,66.392,66.392) |
geographic |
Argentina Rovaniemi |
geographic_facet |
Argentina Rovaniemi |
genre |
Rovaniemi |
genre_facet |
Rovaniemi |
op_rights |
Assumed arXiv.org perpetual, non-exclusive license to distribute this article for submissions made before January 2004 http://arxiv.org/licenses/assumed-1991-2003/ |
op_doi |
https://doi.org/10.48550/arxiv.hep-ph/0202013 |
_version_ |
1766179908754604032 |