Characteristics of the diffuse astrophysical electron and tau neutrino flux with six years of IceCube high energy cascade data

Abstract:

We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010–2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼ 90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ= 2.53±0.07 and a flux normalization for each neutrino flavor of ϕ astro= 1.6 6− 0.27+ 0.25 at E 0= 100 TeV, in agreement with IceCube’s complementary muon neutrino results and with all-neutrino flavor fit results. In the measured energy range we reject spectral indices γ≤ 2.28 at≥ 3 σ significance level. Because of high neutrino energy resolution and low atmospheric neutrino backgrounds …

Año de publicación:

2020

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