An SO(10)XS4 Model of Quark-Lepton Complementarity

Understand

The present observations of Cabbibo angle and solar mixing angle satisfy the empirical relation called Quark-Lepton Complementarity(QLC), namely $\theta_{12}^l\sim \pi/4-\theta_C$.

• It suggests the existence of correlation between quarks and leptons which is supported by the idea of grand unification.
• We propose a specific ansatz for the structure of Yukawa matrices in SO(10) unified theory which leads to such relation if neutrinos get masses through type-II seesaw mechanism.
• Viability of this ansatz is discussed through detailed analysis of fermion masses and mixing angles all of which can be explained in a model which uses three Higgs fields transforming as 10 and one transforming as $\bar{126}$ representations under SO(10).