Standard Model Explanation of the Ultra-high Energy Neutrino Events at IceCube

TL;DR

This paper demonstrates that the Standard Model neutrino interactions can account for IceCube's high-energy neutrino events, suggesting no immediate need for new physics explanations, and highlights IceCube's potential for testing the SM at PeV energies.

Contribution

The study shows that a simple Standard Model explanation with a power-law neutrino flux can explain IceCube's observed events, reducing the necessity for exotic new physics.

Findings

SM neutrino interactions explain all observed events

Power-law flux with spectral index 1.5-2 fits data

IceCube can test SM predictions up to PeV energies

Abstract

The recent observation of two PeV events at IceCube, followed by an additional 26 events between 30 - 300 TeV, has generated considerable speculations on its origin, and many exotic New Physics explanations have been invoked. For a reliable interpretation, it is however important to first scrutinize the Standard Model (SM) expectations carefully, including the theoretical uncertainties, mainly due to the parton distribution functions. Assuming a new isotropic cosmic neutrino flux with a simple unbroken power-law spectrum, $\Phi\propto E^{-s}$ for the entire energy range of interest, we find that with $s=1.5$ - 2, the SM neutrino-nucleon interactions are sufficient to explain all the observed events so far, without the need for any beyond the SM explanation. With more statistics, this powerful detector could provide a unique test of the SM up to the PeV scale, and lead to important clues of New Physics.