# On the Role of the $\nu_\tau$ Appearance in DUNE in Constraining Standard Neutrino Physics and Beyond

## TL;DR

This paper investigates how the $
u_ au$ appearance channel in DUNE can improve constraints on non-standard neutrino interactions and sterile neutrino parameters, without significantly affecting standard oscillation parameter uncertainties.

## Contribution

It provides a detailed analysis of the impact of $
u_ au$ appearance in DUNE on constraining non-standard interactions and sterile neutrino mixing angles, considering various systematic uncertainties and flux configurations.

## Key findings

- $
u_ au$ channel does not reduce standard oscillation uncertainties.
- Significant improvement in sensitivity to $|\e_{\mu au}|$ and $ heta_{34}$.
- Analysis includes different fluxes and systematic assumptions.

## Abstract

We consider the $\nu_\mu \to \nu_{\tau}$ appearance channel in the future Deep Underground Neutrino Experiment (DUNE) which offers a good statistics of the $\nu_{\tau}$ sample. In order to measure its impact on constraining the oscillation parameters, we consider several assumptions on the efficiency for $\nu_\tau$ charged-current signal events (with subsequent $\tau \to e$ decay) and the related backgrounds and study the effects of various systematic uncertainties. Two different neutrino fluxes have been considered, namely a CP-violation optimized flux and a $\nu_\tau$ optimized flux. Our results show that the addition of the $\nu_\mu \to \nu_{\tau}$ appearance channel does not reduce the current uncertainties on the standard 3-$\nu$ oscillation parameters while it can improve in a significant way the sensitivity to the Non-Standard Interaction parameter $|\epsilon_{\mu\tau}|$ and to the new mixing angle $\theta_{34}$ of a sterile neutrino model of the $3+1$ type.