相关论文: Lepton masses and mixing without Yukawa hierarchie…
We present an extension $U(1)_{X}$ to the Standard Model that reproduces the lepton mass structures determined by the experiments. In the charged sector, we introduced effective operators of dimension $n = 7$ to generate the mass of the…
A phenomenological analysis of the three-family model based on the local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ with exotic charged leptons, is carried out. Instead of using the minimal scalar sector able to break the symmetry…
We propose a non-holomorphic modular $A_4$ model under the assumption of universal couplings. In this framework, a charged lepton mass hierarchy is not created through parameter fine tuning or hierarchical Yukawa couplings, but instead is…
We investigate a simple model of neutrino mass based on SU(3)_C X SU(3)_L X U(1)_X gauge unification. The Yukawa coupling of the model has automatic lepton-number symmetry which is broken only by the self-couplings of the Higgs boson. At…
The lepton sector is studied within a flavored non-renormalizable model where the $\mathbf{S}_{3}\otimes \mathbf{Z}_{2}$ flavor symmetry drives the Yukawa couplings. In this framework, the effective neutrino mass, that comes from the type…
We propose a model based on the gauge group $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ with an extra $S_{3}$ flavor symmetry, which accounts for the lepton masses and mixing. The small active neutrino masses are generated via a double…
We discuss conditions under which bi-large mixing in the lepton sector is achieved assuming that all Yukawa matrices and the right-handed neutrino mass matrix have the same singular form in the leading order. Due to obvious quark lepton…
A model based on the local gauge group SU(3)_c x SU(3)_L x U(1)_X without particles with exotic electric charges is shown to be able to provide the quark mass spectrum and their mixing, by means of universal see-saw mechanisms, avoiding a…
We propose a new non-universal $U(1)'$ extension of the standard model with the addition of three exotic quark singlets, two scalar singlets and one additional scalar doublet. We obtain family dependent couplings with a new $Z'$ boson in…
We study the non-Hermitian extension of the Lagrangian of the Standard Model extended by singlet right-handed heavy neutrinos. The Yukawa coupling matrices comprise of hermitian and non-hermitian components and the neutrino mass eigenvalues…
We propose a unique lepton mixing scheme and its association with an exact hierarchy-philic neutrino mass matrix texture in the light of Type-I+Type-II seesaw mechanism under the framework of $A_4 \times Z_{10}$ discrete flavour symmetry.…
The observed hierarchy of quark and lepton masses and mixings may be obtained by adding an abelian family symmetry to the Minimal Supersymmetric Model and coupling quarks and leptons to an electroweak singlet scalar field. In a large class…
Lepton family number violation processes arise in the $SU(6)_L \otimes U(1)_Y$ model due to the presence of an extra neutral gauge boson, Z$'$, with family changing couplings, and due to the fact that this model demands the existence of…
Motivated by the Super-Kamiokande data, we revisit models with U(1) symmetries and discuss the origin of neutrino masses and mixings in such theories. We show that, in models with just three light neutrinos and a hierarchy of neutrino…
A simple ansatz is proposed for neutrino and charged lepton mass matrices, within the framework of universal strength for Yukawa couplings. In this framework all Yukawa couplings have equal moduli and the flavour dependence is only in their…
We propose a scheme in that the masses of the heavier leptons obey seesaw type relations. The light lepton masses, except the electron and the electron neutrino ones are generated by one loop level radiative corrections. We work in a…
We perform a systematic analysis of the PMNS matrices which arise when one assigns the three generations of leptons to the $2\oplus 1$ representation of a horizontal $SU_H(2)$ symmetry. This idea has been previously explored by Kuchimanchi…
We show that the observed structure of quark and lepton masses and mixing angles can arise entirely geometrically from superstring constructions, at the renormalizable level. The model we consider is a $Z_3$ orbifold compactification of…
We consider the generation of neutrino masses via a singly-charged scalar singlet. Under general assumptions we identify two distinct structures for the neutrino mass matrix. This yields a constraint for the antisymmetric Yukawa coupling of…
The exact solution for the neutrino mass matrix of the Zee-Babu model is derived. Tribimaximal mixing imposes conditions on the Yukawa couplings, from which the normal mass hierarchy is preferred. The derived conditions give a possibility…