Viability of $A_4$, $S_4$ and $A_5$ Flavour Symmetries in Light of the First JUNO Result

TL;DR

This paper evaluates the viability of specific discrete flavour symmetries ($A_4$, $S_4$, $A_5$) in explaining neutrino mixing angles, incorporating recent JUNO results and global fit data to refine which models remain plausible.

Contribution

It updates previous analyses by including the first JUNO measurement, narrowing down the viable flavour symmetry models for neutrino mixing.

Findings

Fewer models remain compatible after JUNO data inclusion.

Some models are ruled out at 3σ confidence level.

The viability of certain symmetries depends on neutrino mass ordering.

Abstract

We update the analysis of the viability of the lepton mixing patterns originating from $A_4$, $S_4$ and $A_5$ discrete flavour symmetries and leading to predictions for the solar neutrino mixing angle, $\theta_{12}$. We perform a statistical analysis using as an input (i) the results of the latest global fit to neutrino oscillation data, and (ii) the first JUNO measurement of $\sin^2\theta_{12}$. Out of the five (four) cases compatible with the global data at $3\sigma$ for normal (inverted) neutrino mass ordering, only three (two) cases remain compatible with the global data at the same confidence level after taking into account the JUNO result.