Exploring \nu_\tau - \nu_s mixing with cascade events in DeepCore

TL;DR

This paper investigates the potential of IceCube's DeepCore to detect sterile neutrinos by analyzing cascade events, extending previous muon neutrino studies to include tau neutrino mixing, and demonstrating the ability to constrain the full parameter space.

Contribution

It introduces an analysis of cascade events in IceCube to probe the complete 3+1 sterile neutrino model, including tau neutrino mixing, which was previously unexplored.

Findings

Cascade events can probe the entire 3+1 sterile neutrino parameter space.

IceCube can set constraints on tau neutrino mixing below current limits.

The analysis enhances sensitivity to sterile neutrinos across all flavors.

Abstract

The atmospheric neutrino data collected by the IceCube experiment and its low-energy extension DeepCore provide a unique opportunity to probe the neutrino sector of the Standard Model. In the low energy range the experiment have observed neutrino oscillations, and the high energy data are especially sensitive to signatures of new physics in the neutrino sector. In this context, we previously demonstrated the unmatched potential of the experiment to reveal the existence of light sterile neutrinos. The studies are routinely performed in the simplest 3+1 model concentrating on disappearance of muon neutrinos of TeV energy as a result of their mixing with a sterile neutrino. We here extend this analysis to include cascade events that are secondary electromagnetic and hadronic showers produced by neutrinos of all flavors. We find that it is possible to probe the complete parameter space of 3+1 model, including the poorly constrained mixing of the sterile neutrino to tau neutrinos. We show that $\nu_\tau-\nu_s$ mixing results into a unique signature in the data that will allow IceCube to obtain constraints well below the current upper limits.