Non-standard interactions with high-energy atmospheric neutrinos at IceCube

TL;DR

This paper uses high-energy atmospheric neutrino data from IceCube to set the most stringent constraints to date on non-standard neutrino interactions in the mu-tau sector, accounting for systematic uncertainties and different models.

Contribution

It provides the first tight constraints on the off-diagonal _{} parameter using high-energy IceCube data, including systematic uncertainties and future sensitivity estimates.

Findings

Most stringent bound on _{} to date: -6.0e-3 to 5.4e-3 at 90% credible interval.

Systematic uncertainties and different models significantly impact the constraints.

Projected sensitivity after 10 years could improve bounds and determine non-standard parameters.

Abstract

Non-standard interactions in the propagation of neutrinos in matter can lead to significant deviations from expectations within the standard neutrino oscillation framework and atmospheric neutrino detectors have been considered to set constraints. However, most previous works have focused on relatively low-energy atmospheric neutrino data. Here, we consider the one-year high-energy through-going muon data in IceCube, which has been already used to search for light sterile neutrinos, to constrain new interactions in the $\mu\tau$-sector. In our analysis we include several systematic uncertainties on both, the atmospheric neutrino flux and on the detector properties, which are accounted for via nuisance parameters. After considering different primary cosmic-ray spectra and hadronic interaction models, we obtain the most stringent bound on the off-diagonal $\varepsilon_{\mu \tau}$ parameter to date, with the 90\% credible interval given by $-6.0 \times 10^{-3} < \varepsilon_{\mu \tau} < 5.4 \times 10^{-3}$. In addition, we also estimate the expected sensitivity after 10~years of collected data in IceCube and study the precision at which non-standard parameters could be determined for the case of $\varepsilon_{\mu \tau}$ near its current bound.