DUNE sensitivities to the mixing between sterile and tau neutrinos

TL;DR

This paper evaluates DUNE's potential to detect sterile neutrino mixing with tau neutrinos via neutral-current event analysis, promising significant improvements over existing constraints.

Contribution

It introduces a novel analysis of DUNE's sensitivity to sterile-tau neutrino mixing using neutral-current data, highlighting its potential to advance current bounds.

Findings

DUNE can significantly improve constraints on sterile-tau neutrino mixing.

Neutral-current data at DUNE effectively probes sterile neutrino presence.

Large statistics and event discrimination enhance sensitivity.

Abstract

Light sterile neutrinos can be probed in a number of ways, including electroweak decays, cosmology and neutrino oscillation experiments. At long-baseline experiments, the neutral-current data is directly sensitive to the presence of light sterile neutrinos: once the active neutrinos have oscillated into a sterile state, a depletion in the neutral-current data sample is expected since they do not interact with the $Z$ boson. This channel offers a direct avenue to probe the mixing between a sterile neutrino and the tau neutrino, which remains largely unconstrained by current data. In this work, we study the potential of the DUNE experiment to constrain the mixing angle which parametrizes this mixing, $\theta_{34}$, through the observation of neutral-current events at the far detector. We find that DUNE will be able to improve significantly over current constraints thanks to its large statistics and excellent discrimination between neutral- and charged-current events.