789 research outputs found

    Astrophysical tau neutrinos and their detection by large neutrino telescopes

    Full text link
    We present results of the detailed Monte Carlo calculation of the rates of double-bang events in 1 km3^3 underwater neutrino telescope with taking into account the effects of τ\tau-neutrino propagation through the Earth. As an input, the moderately optimistic theoretical predictions for diffuse neutrino spectra of AGN jets are used.Comment: Talk given at the NANP'03 conference, June 2003. 4 pages, one eps figur

    End of the cosmic neutrino energy spectrum

    Full text link
    There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does not observe either continuum events above 2 PeV, or the Standard Model Glashow-resonance events expected at 6.3 PeV. There are also no higher energy neutrino signatures in the ANITA and Auger experiments. This absence of high-energy neutrino events motivates a fundamental restriction on neutrino energies above a few PeV. We postulate a simple scenario to terminate the neutrino spectrum that is Lorentz-invariance violating, but with a limiting neutrino velocity that is always smaller than the speed of light. If the limiting velocity of the neutrino applies also to its associated charged lepton, then a significant consequence is that the two-body decay modes of the charged pion are forbidden above two times the maximum neutrino energy, while the radiative decay modes are suppressed at higher energies. Such stabilized pions may serve as cosmic ray primaries.Comment: 6 pages. Version to appear in PL