Multi-Higgs-Doublet Models and Singular Alignment

Understand

We consider a 4-Higgs-doublet model in which each Higgs doublet gives mass to one of the fermion sets $\{ m_t\}$, $\{ m_b,m_\tau,m_c \}$, $\{ m_\mu,m_s \}$, and $\{ m_d,m_u,m_e \}$.

• The sets have the feature that within each of them the masses are similar.
• Our model explains the mass hierarchies of the sets by hierarchies of the vacuum expectation values of the Higgs doublets associated to them.
• All Yukawa couplings are therefore of order one.