Lepton mass matrices from a quark-lepton analogy

Abstract

We study the implications of having a similarity between quark and lepton mixing in the Dirac sector of the Standard Model plus the right-handed neutrino. This enable us to describe all masses and mixings in the Dirac sector in terms of only five parameters: three mass scales $m_b$, $m_{\tau}$ and $m_t$, one parameter $\lambda$ describing all the mixings, and a CP violating phase in the quark sector. Then, from experimental data on neutrino masses and mixings, we extract the heavy neutrino mass matrix. The approach considered, although does not contraddict Grand Unified Theories, can help to find other theoretical models of fermion masses.