Nonstandard neutrino interactions and mu-tau reflection symmetry

TL;DR

This paper explores how nonstandard neutrino interactions combined with mu-tau reflection symmetry, modeled via an $S_4$ flavor symmetry, influence neutrino oscillation measurements and constraints in upcoming experiments like DUNE and T2HK.

Contribution

It introduces an $S_4$ flavor model with mu-tau reflection symmetry that constrains NSI parameters and analyzes its impact on neutrino experiment sensitivities.

Findings

NSI parameters are further constrained under mu-tau reflection symmetry.

Mass ordering sensitivity remains robust despite NSIs.

The model provides a framework for understanding neutrino oscillation effects with symmetries.

Abstract

Nonstandard interactions (NSIs), possible subleading effects originating from new physics beyond the Standard Model, may affect the propagation of neutrinos and eventually contribute to measurements of neutrino oscillations. Besides this, $ \mu-\tau $ reflection symmetry, naturally predicted by non-Abelian discrete flavor symmetries, has been very successful in explaining the observed leptonic mixing patterns. In this work, we study the combined effect of both. We present an $S_4$ flavor model with $\mu-\tau$ reflection symmetry realized in both neutrino masses and NSIs. Under this formalism, we perform a detailed study for the upcoming neutrino experiments DUNE and T2HK. Our simulation results show that under the $\mu-\tau $ reflection symmetry, NSI parameters are further constrained and the mass ordering sensitivity is less affected by the presence of NSIs.