Flavor as an Incomplete Structure: Conceptual Questions and the Role of DUNE

TL;DR

The paper discusses the conceptual incompleteness of the flavor structure in the Standard Model and highlights how DUNE's experimental program can test the limits of the current three-flavor framework, especially regarding neutrino properties.

Contribution

It proposes using DUNE's phased measurements and strategies to explore and challenge the current understanding of flavor physics and potential new physics beyond the Standard Model.

Findings

DUNE's long-baseline and near-detector programs can detect small deviations from the three-flavor model.

The DUNE-PRISM strategy improves control over systematic uncertainties in flavor measurements.

Neutrino mass and mixing patterns may reveal new physics through DUNE's sensitivity.

Abstract

Flavor remains one of the most successful yet least understood structures of the Standard Model. The discovery of the Higgs boson completed the electroweak account of mass generation, but did not explain the origin of fermion families, mass hierarchies, or mixing patterns. In this sense, flavor can be regarded as an empirically successful but conceptually incomplete structure. Neutrinos occupy a particularly sensitive place within this problem: their masses are tiny, their mixing is large, and their mass-generation mechanism may differ from that of charged fermions. In this article, we discuss flavor as an open conceptual problem and argue that DUNE, as a phased program spanning precision oscillation measurements and sensitivity to BSM and dark-sector phenomena, provides a powerful framework for testing the self-consistency and possible limits of the present three-flavor description. In particular, the complementarity between the long-baseline program and the Phase I near-detector complex, together with the DUNE-PRISM strategy for controlling interaction-model systematics and enabling data-driven near-to-far predictions, makes DUNE especially well-suited to search for small, correlated departures from the minimal flavor framework.