S_4 Flavor Symmetry Embedded into SU(3) and Lepton Masses and Mixing
Abstract
Description
Based on an assumption that an S_4 flavor symmetry is embedded into SU(3), a lepton mass matrix model is investigated. A Frogatt-Nielsen type model is assumed, and the flavor structures of the masses and mixing are caused by VEVs of SU(2)_L-singlet scalars ϕ_u and ϕ_d which are nonets (8+1) of the SU(3) flavor symmetry, and which are broken into 2+3+3' and 1 of S_4. If we require the invariance under the transformation (ϕ^{(8)},ϕ^{(1)}) \to (-ϕ^{(8)},+ϕ^{(1)}) for the superpotential of the nonet field ϕ^{(8+1)}, the model leads to a beautiful relation for the charged lepton masses. The observed tribimaximal neutrino mixing is understood by assuming two SU(3) singlet right-handed neutrinos ν_R^{(\pm)} and an SU(3) triplet scalar χ.
12 pages, no figure, to appear on JHEP
12 pages, no figure, to appear on JHEP