$\Delta \left(27\right)$ flavor singlet-triplet Higgs model for fermion masses and mixings

Abstract

We propose a multiscalar singlet extension of the singlet-triplet Higgs model capable of explaining the SM fermion mass spectrum and mixing parameters. Our model is based on the $\Delta \left(27\right)$ family symmetry, supplemented by cyclic symmetries, which are spontaneously broken thus yielding the observed hierarchy of the SM charged fermion masses and quark mixing angles. The masses of the light active neutrinos are produced by type-II seesaw mechanism mediated by the neutral component of the $SU(2{)}_L$ scalar triplet. The model symmetries lead to the extended Gatto-Sartori-Tonin relations between the quark masses and mixing angles.

Comments: Revised version. Discussion enlarged, text improved. References added. 19 pages, 2 figures