Leptonic $CP$ violating Phase in the Yukawaon Model

TL;DR

This paper refines the Yukawaon model by unifying VEV forms, leading to updated parameter fits that predict neutrino mixing angles and CP violation phases consistent with recent experimental observations.

Contribution

It introduces a unified VEV form in the Yukawaon model, enabling revised fits for quark and lepton masses and mixings, and predicts neutrino CP violation parameters aligned with recent data.

Findings

Predicted neutrino mixing angle $ heta_{13}$ matches observed values.

Predicted leptonic CP phase $\delta_{CP}^ ext{lepton}$ aligns with T2K results.

Updated model provides a consistent description of quark and lepton flavor parameters.

Abstract

In the so-called "Yukawaon" model, the (effective) Yukawa coupling constants $Y_f^{eff}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$ (Yukawaons) with $3\times 3$ components. In this brief report, we change VEV forms $<Y_f>$ in the previous paper into a unified form. Therefore, parameter fitting for quark and lepton masses and mixings is revised. Especially, we obtain predicted values of neutrino mixing $\sin^2 2\theta_{13}$ and a leptonic $CP$ violating phase $\delta_{CP}^\ell$ which are consistent with the observed curve in the $(\sin^2 2\theta_{13}, \delta_{CP}^\ell)$ reported by T2K group recently.