Related papers: Unification with and without Supersymmetry: Adjoin…
We present a simple scenario for gauge mediated supersymmetry breaking where the messengers are also the fields that generate neutrino masses. We show that the simplest such scenario corresponds to the case where neutrino masses are…
We review the known ways of incorporating and breaking symmetries in a renormalizable way. We summarize the various grand unified theories based on $SU_5, SO_{10}$, and $E_6$ as family enlargement groups. An $SU_5$ model with an $SU_2$…
We construct a supersymmetric (SUSY) $SU(5)$ model with the flavor symmetry $S_4\times Z_3\times Z_4$. Three generations of adjoint matter fields are introduced to generate the neutrino masses via the combined type I and type III see-saw…
Given the tremendous phenomenological success of the Standard Model (SM) framework, it becomes increasingly important to understand to what extent its specific structure dynamically emerges from unification principles. In this study, we…
We propose a model with $D_4$ flavor symmetry for leptogenesis in the framework of supersymmetric $SU(5)$ grand unified theory. Neutrino masses arise from the type I seesaw mechanism where the spontaneous symmetry breaking of the flavor…
We discuss the implications of large neutrino mixings for grand unified theories based on the seesaw mechanism. In SU(5) GUTs large mixings can be accomodated by means of $U(1)_F$ flavour symmetries. In these models the heavy Majorana…
In the minimal standard electroweak gauge model, there is an effective dimension-five operator which generates neutrino masses, and it has only three tree-level realizations. One is the canonical seesaw mechanism with a right-handed…
The implementation of seesaw mechanisms to give mass to neutrinos in the presence of an anomaly-free U(1)_X gauge symmetry is discussed in the context of minimal extensions of the standard model. It is shown that type-I and type-III seesaw…
The problem of neutrino masses and mixing angles is analysed in a class of supersymmetric grand unified models, with SO(10) gauge symmetry and global U(2) flavour symmetry. Adopting the seesaw mechanism for the generation of the neutrino…
This paper starts with the most basic SU(5) Grand Unified Theory, coupled to Supergravity. Then it builds a new theory, incorporating the ideas of Suppressed SUSY. Suppressed SUSY is an alternative to the spontaneous breaking of SUSY. It…
We investigate a simple realistic grand unified theory based on the $SU(5)$ gauge symmetry which predicts an upper bound on the proton decay lifetime for the channels $p \to K^+ \bar{\nu}$ and $p \to \pi^+ \bar{\nu}$, i.e. $\tau (p \to K^+…
Alternatives to the traditional grand unified theory seesaw for neutrino masses are briefly described. These include the possibility of large extra dimensions and various possibilities for models involving an extra U(1)' gauge symmetry. The…
We investigate supersymmetric scenarios in which neutrino masses are generated by effective d=6 operators in the Kahler potential, rather than by the standard d=5 superpotential operator. First, we discuss some general features of such…
We explore generating the dimension five operator leading to neutrino masses by integrating out heavy SU(2)_L triplet fermions. We exhibit a model that has a neutrino mass matrix consistent with observations. In addition, the model is…
Theories in which neutrino masses are generated by a conventional see-saw mechanism generically yield masses which are O(v^2) in units where M_{Pl}=1, which is naively too small to explain the results from SuperKamiokande. In supersymmetric…
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…
We describe a supersymmetric Grand Unified Theory based on the gauge group $\SU(5)^3$, or $\SO(10)^3$, invariant under the interchange of any~SU(5), or~SO(10), with each family multiplet transforming non trivially under one different…
Given that dark matter and normal matter are nontrivially unified in a grand unified theory, called dark grand unification, we derive novel residual theories at low energy explaining dark matter and neutrino mass. The first chain of which…
The see-saw mechanism for neutrino masses based on the Grand Unification leads to the mass of the heaviest neutrino ($\approx \nu_{\tau}$) in the range $(2 - 3)\cdot 10^{-3}$ eV and hence to a solution of the solar neutrino problem through…
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…