Methods and stability tests associated with the sterile neutrino search using improved high-energy $\nu_\mu$ event reconstruction in IceCube

TL;DR

This paper details an eleven-year search for sterile neutrinos using IceCube data, highlighting improved reconstruction methods, systematic uncertainty analysis, and stability tests that support the robustness of the findings.

Contribution

The study introduces enhanced event reconstruction and systematic analysis techniques for sterile neutrino searches in IceCube data, with stability tests confirming result consistency.

Findings

Best-fit sterile neutrino parameters: sin^2(2θ24)=0.16, Δm^2_41=3.5 eV^2

Goodness-of-fit p-value of 12%, consistent with no sterile neutrino oscillations (p=3.1%)

Results are stable across data splits and improved analysis methods

Abstract

We provide supporting details for the search for a 3+1 sterile neutrino using data collected over eleven years at the IceCube Neutrino Observatory. The analysis uses atmospheric muon-flavored neutrinos from 0.5 to 100\, TeV that traverse the Earth to reach the IceCube detector, and finds a best-fit point at $\sin^2(2\theta_{24}) = 0.16$ and $\Delta m^{2}_{41} = 3.5$ eV$^2$ with a goodness-of-fit p-value of 12\% and consistency with the null hypothesis of no oscillations to sterile neutrinos with a p-value of 3.1\%. Several improvements were made over past analyses, which are reviewed in this article, including upgrades to the reconstruction and the study of sources of systematic uncertainty. We provide details of the fit quality and discuss stability tests that split the data for separate samples, comparing results. We find that the fits are consistent between split data sets.