Related papers: Type III Seesaw and Left-Right Symmetry
We propose a $B-L$ gauged extension of the Standard Model where light neutrino masses arise from type III seesaw mechanism. Unlike the minimal $B-L$ model with three right handed neutrinos having unit lepton number each, the model with…
We show that the type-I seesaw, responsible for generating the light neutrino mass, itself is capable of accommodating one of the three right handed neutrinos as a freeze-in type of dark matter (DM) where the required smallness of the…
It is shown that the type III seesaw mechanism proposed recently can have certain advantages over the conventional (or type I) seesaw mechanism for leptogenesis. In particular a resonant enhancement of leptogenesis via heavy quasi-Dirac…
Seesaw mechanisms are the simplest and the most elegant way of generating small masses for the active neutrinos $(m_\nu)$. In these mechanisms $m_\nu$ is inversely proportional to the lepton number breaking scale $(M)$ that, in the…
In the framework of type II seesaw mechanism we propose two simple but instructive ansatze for neutrino mixing and leptogenesis. In each ansatz, the effective Majorana neutrino mass matrix is composed of two parts -- the part with Z_2…
The possibility to explain the baryon asymmetry in the Universe through the leptogenesis mechanism in the context of Adjoint SU(5) is investigated. In this model the neutrino masses are generated through the Type I and Type III seesaw…
We study the model with three right-handed neutrinos which masses are smaller than the weak scale ${\cal O}(10^2)$ GeV (called as the $\nu$MSM). The model can explain the origin of neutrino masses by the seesaw mechanism, offer a candidate…
The type III seesaw mechanism for neutrino mass generation usually makes use of at least two $Y = 0$, $SU(2)_L$ lepton triplets. We augment such a model with a third triplet and a sterile neutrino, both of which are odd under a conserved…
We propose two Type-II seesaw scenarios for the neutrino mass matrix in the left-right symmetric model, in which the Higgs triplet Yukawa coupling matrix takes the appealing Friedberg-Lee texture. We show that the nearly tri-bimaximal…
We introduce a method to extract the right-handed neutrino mass matrix from the Left-Right symmetric seesaw formula and apply it to the study of a simple SUSY SO(10) theory. We find 8 possible solutions for the heavy neutrino spectrum and a…
Extending the Standard Model with right-handed neutrinos provides a minimal explanation for both light neutrino masses (through the type-I seesaw mechanism) and the baryon asymmetry of our universe (through leptogenesis). We map here for…
We study a model of neutrino and dark matter within the framework of a minimal extended seesaw. This framework is based on $A_4$ flavor symmetry along with the discrete $Z_4$ symmetry to stabilize the dark matter and construct desired mass…
We study leptogenesis in three different realisations of the type Ib seesaw mechanism, where the effective masses of the neutrinos are obtained by the spontaneous symmetry breaking of two different Higgs doublets. In the minimal type Ib…
In this talk we show how a natural neutrino mass hierarchy can follow from the type I see-saw mechanism, and a natural neutrino mass degeneracy from the type II see-saw mechanism, where the bi-large mixing angles can arise from either the…
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…
Type I and type II seesaw contributions to the mass matrix of light neutrinos are inherently related if left-right symmetry is realized at high energy scales. We investigate implications of such a relation for the interpretation of neutrino…
Right-handed neutrinos $N$ are introduced to explain the origin of the tiny neutrino masses via the seesaw mechanism. Required by relatively large Yukawa coupling and leptogenesis, masses of right-handed neutrinos are beyond $10^{9}$ GeV.…
We propose a gauged $U(1)_{B-L}$ extension of the standard model (SM) to explain simultaneously the light neutrino masses and dark matter (DM). The generation of neutrino masses occurs through a variant of type-II seesaw mechanism in which…
The seesaw mechanism of neutrino mass generation is analysed under the following assumptions: (1) minimal seesaw with no Higgs triplets, (2) hierarchical Dirac masses of neutrinos, (3) large lepton mixing primarily or solely due to the…
The seesaw type II mechanism is considered within the framework of a left-right chiral model with a gauge group $SU(2)_L\times SU(2)_R\times U(1)$, the lepton sector of which includes three generations of heavy Majorana neutrinos. The…