Quark and Lepton Mass Matrix Model with Only Six Family-Independent Parameters

Abstract

We propose a unified mass matrix model for quarks and leptons, in which sixteen observables of mass ratios and mixings of the quarks and neutrinos are described by using no family number-dependent parameters except for the charged lepton masses and only six family number-independent free parameters. The model is constructed by extending the so-called "Yukawaon" model to a seesaw type model with the smallest number of possible family number-independent free parameters. As a result, once the six parameters is fixed by the quark mixing and the mass ratios of quarks and neutrinos, no free parameters are left in the lepton mixing matrix. The results are in excellent agreement with the neutrino mixing data. We predict $\delta_{CP}^\ell =-68^\circ$ for the leptonic $CP$ violating phase and $\langle m\rangle\simeq 21$ meV for the effective Majorana neutrino mass.