http://arxiv.org/abs/2001.09520
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 ($\sim 90 \%$) by electron and tau flavors. The flux, observed in the energy range from $16\,\mathrm{TeV} $ to $2.6\,\mathrm{PeV}$, is consistent with a single power-law as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be $\gamma=2.53\pm0.07$ and a flux normalization for each neutrino flavor of $\phi_{astro} = 1.66^{+0.25}{-0.27}$ at $E{0} = 100\, \mathrm{TeV}$. This flux of electron and tau neutrinos is in agreement with IceCube muon neutrino results and with all-neutrino flavor results. Results from fits assuming more complex neutrino flux models suggest a flux softening at high energies and a flux hardening at low energies (p-value $\ge 0.06$).
I. Collaboration, M. Aartsen, M. Ackermann, et. al.
Tue, 28 Jan 20
37/63
Comments: 4 figures, 4 tables, includes supplementary material