New physics from oscillations at the DUNE near detector, and the role of systematic uncertainties

TL;DR

This paper evaluates DUNE near detector's ability to detect new physics in neutrino oscillations, emphasizing the critical impact of spectral uncertainties and the need for improved understanding of systematic effects.

Contribution

It provides a comprehensive analysis of the DUNE near detector's sensitivity to various new physics scenarios, including the role of spectral uncertainties and the ${ u}_{ au}$ appearance channel.

Findings

Spectral uncertainties can reduce sensitivity to sterile neutrinos by over two orders of magnitude.

Improving spectral uncertainties below 5% enhances the potential to detect new physics.

Systematic uncertainties significantly influence the interpretation of neutrino oscillation data.

Abstract

We study the capabilities of the DUNE near detector to probe deviations from unitarity of the leptonic mixing matrix, the 3+1 sterile formalism and Non-Standard Interactions affecting neutrino production and detection. We clarify the relation and possible mappings among the three formalisms at short-baseline experiments, and we add to current analyses in the literature the study of the ${\nu}_{\mu} \rightarrow {\nu}_{\tau}$ appearance channel. We study in detail the impact of spectral uncertainties on the sensitivity to new physics using the DUNE near detector, which has been widely overlooked in the literature. Our analysis shows that this plays an important role on the results and, in particular, that it can lead to a strong reduction in the sensitivity to sterile neutrinos from ${\nu}_{\mu} \rightarrow {\nu}_e$ transitions, by more than two orders of magnitude. This stresses the importance of a joint experimental and theoretical effort to improve our understanding of neutrino nucleus cross sections, as well as hadron production uncertainties and beam focusing effects. Nevertheless, even with our conservative and more realistic implementation of systematic uncertainties, we find that an improvement over current bounds in the new physics frameworks considered is generally expected if spectral uncertainties are below the $5\%$ level.