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

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 $δ_D$. Without involving model parameters, the probability distribution of $δ_D$ 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 $δ_D$ and the atmospheric angle $θ_a \equiv θ_{23}$.

Figures (2)

• Figure 1: The predicted probability distributions of the leptonic Dirac CP phase according to the residual $\mathbb Z^s_2$ (red) or $\overline{\mathbb Z}^s_2$ (blue) symmetries with inputs from the current NuFIT 6.0 global fit plus the JUNO first data release. In addition, the CP phase probability distributions from the NuFIT 6.0 global fit (purple dashed) and the T2K plus NOvA joint analysis (cyan dashed) are also shown for comparison. Both normal (NO) and inverted (IO) orderings have been shown in the upper and lower panels, respectively.
• Figure 2: Comparison between the theoretical prediction of the residual $\mathbb Z^s_2$ (red) or $\overline{\mathbb Z}^s_2$ (blue) symmetries and the latest NuFIT 6.0 results (green) for the two-dimensional correlated probability distributions between the atmospheric angle $\theta_a$ and the leptonic Dirac CP phase $\delta_D$. The upper panel is for NO while the lower one is for IO.