Sterile sector impacting the correlations and degeneracies among mixing parameters at the Deep Underground Neutrino Experiment

TL;DR

This paper analyzes how the Deep Underground Neutrino Experiment (DUNE) can detect and constrain active-sterile neutrino mixing, providing analytic formulas and exploring parameter correlations to enhance sensitivity.

Contribution

It offers new analytic expressions for oscillation probabilities involving sterile neutrinos and studies their correlations with standard parameters at DUNE.

Findings

DUNE can significantly improve sensitivity to sterile neutrino parameters.

Charged and neutral current interactions enhance detection prospects.

Parameter correlations impact the interpretation of sterile neutrino signals.

Abstract

We investigate the physics potential of the upcoming Deep Underground Neutrino Experiment (DUNE) in probing active-sterile mixing. We present analytic expressions for relevant oscillation probabilities for three active and one sterile neutrino of eV-scale mass and highlight essential parameters impacting the oscillation signals at DUNE. We then explore the space of sterile parameters as well as study their correlations among themselves and with parameters appearing in the standard framework ($\delta_{13}$ and $\theta_{23}$). We perform a combined fit for the near and far detector at DUNE using GLoBES. We consider alternative beam tune (low energy and medium energy) and runtime combinations for constraining the sterile parameter space. We show that charged current and neutral current interactions over the near and far detector at DUNE allow for an improved sensitivity for a wide range of sterile neutrino mass splittings.