Large $\theta_{13}^\nu$ and Unified Description of Quark and Lepton Mixing Matrices

TL;DR

This paper revises the yukawaon model to better unify quark and lepton mixing matrices, successfully predicting a sizable neutrino mixing angle while maintaining accurate quark and lepton mass ratios.

Contribution

It introduces a phenomenological modification to the yukawaon model, allowing different structures for neutrino Dirac and charged lepton mass matrices, improving predictive power.

Findings

Predicts $ heta_{13}$ mixing angle $ o 0.07$

Maintains successful quark and lepton mass ratios

Unifies quark and lepton mixing descriptions

Abstract

We present a revised version of the so-called "yukawaon model", which was proposed for the purpose of a unified description of the lepton mixing matrix $U_{PMNS}$ and the quark mixing matrix $V_{CKM}$. It is assumed from a phenomenological point of view that the neutrino Dirac mass matrix $M_D$ is given with a somewhat different structure from the charged lepton mass matrix $M_e$, although $M_D=M_e$ was assumed in the previous model. As a result, the revised model predicts a reasonable value $\sin^2 2\theta_{13} \sim 0.07$ with keeping successful results for other parameters in $U_{PMNS}$ as well as $V_{CKM}$ and quark and lepton mass ratios.