title: Unstable superheavy relic particles as a source of neutrinos responsible for ultrahigh-energy cosmic rays
abstract: Decays of superheavy relic particles may produce extremely energetic neutrinos. Their annihilations on the relic neutrinos can be the origin of the cosmic rays with energies beyond the Greisen-Zatsepin-Kuzmin cutoff. The redshift acts as a cosmological filter selecting the sources at some particular value z(e)+/-deltaz, for which the present neutrino energy is close to the Z pole of the annihilation cross section. We predict no directional correlation of the ultrahigh-energy cosmic rays with the galactic halo. At the same time, there can be some directional correlations in the data, reflecting the distribution of matter at redshift z = z(e)+/-deltaz. Both of these features are manifest in the existing data. Our scenario is consistent with the neutrino mass reported by super-Kamiokande and requires no lepton asymmetry or clustering of the background neutrinos.
authors.affiliation: Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547, USA.
authors.initials: G
authors.lastname: Gelmini
authors.initials: A
authors.lastname: Kusenko