CP Prediction from Residual $\mathbb Z_2^s$ and $\overline{\mathbb Z}_2^s$ Symmetries with JUNO First Data

TL;DR

This paper uses residual $ ext{Z}_2$ symmetries and recent experimental data to predict the leptonic CP phase $ ext{δ}_D$, comparing predictions with global fits and experiments to assess symmetry preferences.

Contribution

It introduces a model-independent method to predict the CP phase using residual symmetries and recent data, including a detailed correlation analysis with mixing angles.

Findings

Bayesian analysis favors certain residual symmetries based on data

Predicted $ ext{δ}_D$ distributions align with global fit results

Correlation between $ ext{δ}_D$ and $ heta_{23}$ is quantitatively characterized

Abstract

The JUNO first data and the recent neutrino global fit results are implemented in the sum rule from the residual $\mathbb Z^s_2$ and $\overline{\mathbb Z}^s_2$ symmetries to make prediction of the leptonic Dirac CP phase $\delta_D$. Without involving model parameters, the probability distribution of $\delta_D$ can be readily obtained from the experimental measurements of the three mixing angles. We then confront the theoretical predictions with the global fit results for the CP phase as well as the T2K and NOvA joint analysis for their CP measurement to give the data preference of the two residual symmetries with Bayes factor for both normal and inverted orderings. We further extend our analysis to a two-dimensional probability distribution to fully explore the correlation between the CP phase $\delta_D$ and the atmospheric angle $\theta_a \equiv \theta_{23}$.