Combining Sterile Neutrino Fits to Short Baseline Data with IceCube Data

TL;DR

This paper integrates IceCube data into global fits for sterile neutrino models, demonstrating that the unstable sterile neutrino (3+1+decay) model significantly improves fit quality and reduces dataset tensions compared to the standard 3+1 model.

Contribution

It introduces IceCube data into sterile neutrino global fits, showing the 3+1+decay model's superior performance and tension reduction over the standard 3+1 model.

Findings

3+1+decay model fits data better than 3+1

Significant tension reduction between datasets

5.4σ improvement over null hypothesis

Abstract

Recent global fits to short-baseline neutrino oscillation data have been performed finding preference for a sterile neutrino solution (3+1) over null. In the most recent iteration, it was pointed out that an unstable sterile neutrino (3+1+decay) may be a better description of the data. This is due to the fact that this model significantly reduces the tension between appearance and disappearance datasets. In this work, we add a one-year IceCube dataset to the global fit obtaining new results for the standard 3+1 and 3+1+decay sterile neutrino scenarios. We find that the 3+1+decay model provides a better fit than the 3+1, even in the presence of IceCube, with reduced appearance to disappearance tension. The 3+1+decay model is a 5.4$\sigma$ improvement over the null hypothesis and a 2.8$\sigma$ improvement over the standard 3+1 model.