Robust flavor equalization of cosmic neutrino flux by quasi bi-maximal mixing

TL;DR

This paper re-derives the expected cosmic neutrino flavor ratios using quasi bi-maximal mixing and discusses how observed ratios may not directly reflect the source flux composition.

Contribution

It demonstrates that the observed flavor ratios do not necessarily confirm the source flux ratios, challenging previous assumptions based on neutrino oscillation models.

Findings

Re-derivation of AJY results using quasi bi-maximal mixing

Observation of 1:1:1 flavor ratio does not confirm source flux of 1:2:0

Highlights the importance of mixing models in interpreting neutrino data

Abstract

For high energy cosmic neutrinos Athar, Jezabek, and Yasuda (AJY) have recently shown that the existing data on neutrino oscillations suggests that cosmic neutrino flux at the AGN/GRB source, F(nu_e):F(nu_mu):F(nu_tau) approx 1:2:0, oscillates to F(nu_e):F(nu_mu):F(nu_tau) approx 1:1:1. These results can be confirmed at AMANDA, Baikal, ANTARES and NESTOR, and other neutrino detectors with a good flavor resolution. Here, we re-derive the AJY result from quasi bi-maximal mixing, and show that observation of F(nu_e):F(nu_\mu):F(nu_tau) approx 1:1:1 does not necessarily establish cosmic neutrino flux at the AGN/GRB source to be F(nu_e):F(nu_mu):F(nu_tau) approx 1:2:0.