相关论文: The Type-II Singular See-Saw Mechanism

We investigate an alternative seesaw mechanism for neutrino mass generation. Neutrino mass is generated at loop level but the basic concept of usual seesaw mechanism is kept. One simple model is constructed to show how this mechanism is…

Type-I seesaw provides a natural explanation for the tiny neutrino masses. The right-handed neutrino masses it requires are, however, too large to keep the Higgs boson mass at its measured value. Here we show that vector-spinors, singlet…

In this paper we consider possible mechanisms to generate small Majorana neutrino masses for active neutrinos in the scenario of gauge-Higgs unification, a candidate for physics beyond the standard model. We stress that it is non-trivial to…

In this talk we assume the conventional see-saw mechanism, and contruct a hierarchical pattern of three active neutrinos with bi-maximal mixing. In order to enforce the hierarchy we use the single right handed neutrino dominance mechanism…

Stimulated by the recent development of the ``universal seesaw mass matrix model", an application of the model to the neutrino mass matrix is investigated: For the charged lepton and down-quark sectors, the model explains the smallness of…

A four-neutrino spectrum with a sterile neutrino without significant involvement in the atmospheric and solar neutrino oscillation experiments has been recently advocated as the correct picture to explain all existing experimental data. We…

We propose a type II upgrade of type I see-saw models leading to new classes of models where partially degenerate neutrinos are as natural as hierarchical ones. The additional type II contribution to the neutrino mass matrix, which…

As an alternative for popular see-saw mechanism, the option of three pseudo% -Dirac neutrinos is discussed, where ${1/2}(m^{(L)} + m^{(R)}) \ll m^{(D)}$ for their Majorana and Dirac masses. The actual neutrino mass matrix is assumed in the…

Opening up the Weinberg operator at 1-loop level using a scalar triplet, two scalar doublets and one fermion gives rise to T4-2-i one-loop topology. Neutrino masses generated from this topology are always accompanied by the tree level Type…

We reformulate the canonical seesaw mechanism in the case that the electroweak gauge symmetry is unbroken, and show that it can "formally" work and allow us to derive an exact seesaw formula for the light and heavy Majorana neutrinos. We…

Motivated by recent results from neutrino experiments, we study the neutrino masses and mixing in the framework of a SUSY $SU(5)\times \mathbb{A}_{4} $ model. The hybrid of Type I and Type II seesaw mechanisms leads to the nonzero value of…

We present an analysis of normal and inverted hierarchical neutrino mass models within the framework of tri-bi-maximal (TBM) mixing. Considering the neutrinos to be quasi-degenerate (QDN), we study two different neutrino mass models with…

The implementation of the Type III seesaw mechanism for neutrino masses in the context of left-right theories where parity is broken spontaneously is investigated. We propose a simple left-right symmetric theory where the neutrinos masses…

Symplectic flavour symmetry group Sp(n/2) (n is even) of n Majorana states does not allow for invariant Majorana masses. Only specific mass matrices with diagonal and nondiagonal elements are possible here. As a result of the spontaneous…

We consider an existing framework of models where the neutrino Dirac and Majorana mass terms are related, and clarify how the mass structures interact through the type I seesaw mechanism, producing exact tri-bi-maximal mixing for the…

Generating appropriate tiny neutrino masses via inverse seesaw mechanism within the framework of a particular SU(3)xSU(4)xU(1) gauge model is the main outcome of this letter. It is achieved by simply adding three singlet exotic Majorana…

We study a mechanism of generation of Majorana neutrino mass due to spontaneous breaking of chiral symmetry (SBCS) accompanied by the formation of a quark condensate. The effect of the condensate is transmitted to the neutrino sector via…

We consider the mechanism of screening of the Dirac flavor structure in the context of the double seesaw mechanism. As a consequence of screening, the structure of the light neutrino mass matrix, m_\nu, is determined essentially by the…

One of the main purposes of SHiP experiment is to shed light on neutrino mass generation mechanisms like the so-called seesaw. We consider a minimal type-I seesaw neutrino mass mechanism model with two heavy neutral leptons (right-handed or…

We propose a model for lepton mass matrices based on the seesaw mechanism, a complex scalar gauge singlet and a horizontal symmetry $S_3 \times \mathbbm{Z}_2$. In a suitable weak basis, the charged-lepton mass matrix and the neutrino Dirac…