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arXiv · 1412.8264

The spectrum and flavor composition of the astrophysical neutrinos in IceCube

Atsushi Watanabe
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Abstract

We fit the energy distribution of the IceCube starting events by a model which involves four parameters in the neutrino spectrum, namely three normalizations $n_e,n_μ,n_τ$ and a common power-law index $γ$, with a fixed background simulated by IceCube. It is found that the best fit index is $γ= 2.7$ with $χ^2_{\rm min} = 32.3/24\,{\rm dof}$. As for the two parameter model involving a democratic normalization and an index, the best fit is at $γ= 2.8$ with $χ^2_{\rm min} = 33.9/26\,{\rm dof}$. The flavored model and the democratic model do not have much difference in the quality of the (energy-spectrum) fit. The standard $1:1:1$ composition is not disfavored by the current data.

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Atsushi Watanabe. 2015-08-18. The spectrum and flavor composition of the astrophysical neutrinos in IceCube. https://doi.org/10.1088/1475-7516%2F2015%2F08%2F030

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