1206.6362 (A. G. Dias et al.)

An $S_3$ Model for Lepton Mass Matrices with Nearly Minimal Texture    [PDF]

A. G. Dias, A. C. B. Machado, C. C. Nishi

We propose a simple extension of the electroweak standard model based on the discrete $S_3$ symmetry that is capable of realizing a nearly minimal Fritzsch-type texture for both the Dirac mass matrices of charged leptons and neutrinos. This is achieved with aid of two additional $Z_3$ symmetries, one of which can be embedded in $U(1)_{B-L}$. Four complex scalar singlet fields are introduced in addition to the SM with righthanded neutrinos. Although more general, the modified texture of the model retains the successful features of the minimal texture without fine-tuning, namely, it accommodates the masses and mixing of the leptonic sector and relates the emergence of large leptonic mixing angles with the seesaw mechanism. An analysis of deviations from the minimal texture ansatz is also presented.

View original: http://arxiv.org/abs/1206.6362