Ultrahigh-energy neutrino scattering onto relic light neutrinos in galactic halo as a possible source of highest energy extragalactic cosmic rays

Sep, 1997
18 pages
Published in:
  • Astrophys.J. 517 (1999) 725-733
e-Print:
Report number:
  • ROME1-1179-97

Citations per year

1997200420112018202401020304050
Abstract: (arXiv)
The diffuse relic neutrinos with light mass are transparent to Ultrahigh energy (UHE) neutrinos at thousands EeV, born by photoproduction of pions by UHE protons on relic 2.73 K BBR radiation and originated in AGNs at cosmic distances. However these UHE ν\nus may interact with those (mainly heaviest νμr\nu_{\mu_r}, ντr\nu_{\tau_r} and respective antineutrinos) clustered into HDM galactic halos. UHE photons or protons, secondaries of ννr\nu\nu_r scattering, might be the final observed signature of such high-energy chain reactions and may be responsible of the highest extragalactic cosmic-ray (CR) events. The chain-reactions conversion efficiency, ramifications and energetics are considered for the October 1991 CR event at 320 EeV observed by the Fly's Eye detector in Utah. These quantities seem compatible with the distance, direction and power (observed at MeV gamma energies) of the Seyfert galaxy MCG 8-11-11. The ννr\nu\nu_r interaction probability is favoured by at least three order of magnitude with respect to a direct ν\nu scattering onto the Earth atmosphere. Therefore, it may better explain the extragalactic origin of the puzzling 320 EeV event, while offering indirect evidence of a hot dark galactic halo of light (i.e., mνm_\nu\sim tens eV) neutrinos, probably of tau flavour.
  • neutrino: cosmic radiation
  • neutrino: cluster
  • particle source: galaxy
  • photon p: interaction
  • pi: photoproduction
  • pi: decay
  • channel cross section: energy dependence
  • neutrino antineutrino: interaction
  • W: pair production
  • p: production