Neutrino flavor ratio on Earth and at astrophysical sources

We present the reconstruction of neutrino flavor ratios at astrophysical sources. For distinguishing the pion source and the muon-damped source to the 3 σ level, the neutrino flux ratios, R ≡ ϕ ( ν μ ) / ( ϕ ( ν e ) + ϕ ( ν τ ) ) and S ≡ ϕ ( ν e ) / ( ϕ ( ν τ ) ) , need to be measured in accuracies better than 10%.