Ambiguity in source flux of high-energy cosmic/astrophysical neutrinos: Effects of bi-maximal mixing and quantum-gravity induced decoherence

摘要

For high energy cosmic neutrinos Athar, Jezabek, and Yasuda (AJY) haverecently shown that the existing data on neutrino oscillations suggests thatcosmic neutrino flux at the AGN/GRB source, F(nu_e):F(nu_mu):F(nu_tau) approx1:2:0, oscillates to F(nu_e):F(nu_mu):F(nu_tau) approx 1:1:1. These results canbe confirmed at AMANDA, Baikal, ANTARES and NESTOR, and other neutrinodetectors with a good flavor resolution. Here, we re-derive the AJY result fromquasi bi-maximal mixing, and show that observation ofF(nu_e):F(nu_mu):F(nu_tau) approx 1:1:1 does not necessarily establish cosmicneutrino flux at the AGN/GRB source to be F(nu_e):F(nu_mu):F(nu_tau) approx1:2:0. We also note that if the length scale for the quantum-gravity inducedde-coherence for astrophysical neutrinos is of the order of a Mpc, thenindependent of the MNS matrix, the Liu-Hu-Ge (LHG) mechanism would lead to fluxequalization for the cosmic/astrophysical neutrinos.