Related papers: Witten's loop in the flipped SU(5) unification
In the simplest potentially realistic renormalizable variants of the flipped $SU(5)$ unified model the right-handed neutrino masses are conveniently generated by means of the Witten's two-loop mechanism. As a consequence, the compactness of…
We argue that the Witten's loop mechanism for the right-handed Majorana neutrino mass generation identified originally in the SO(10) grand unification context can be successfully adopted to the class of the simplest flipped SU(5) models. In…
We propose a simple renormalizable grand unified theory based on the $SU(5)$ gauge symmetry where the neutrino masses are generated at the quantum level through the Zee mechanism. In this model the same Higgs needed to correct the mass…
We revisit the doublet-triplet splitting problem within the $SU(5)$ gauge group framework to advocate a viable regime with the light scalar leptoquark of the doublet-triplet splitting notoriety that is compatible with the current…
In this work we propose a renormalizable model based on the $SU(5)$ gauge group where neutrino mass originates at the two-loop level without extending the fermionic content of the Standard Model (SM). Unlike the conventional $SU(5)$ models,…
We investigate the low energy properties of an effective local model with flipped $SU(5)\times U(1)_{\chi}$ gauge group, constructed within the framework of F-theory. Its origin is traced back to the $SO(10)$ symmetry -- associated with a…
It is shown that embedding a four-dimensional flipped SU(5) model in a five-dimensional SO(10) model, preserves the best features of both flipped SU(5) and SO(10). The missing partner mechanism, which naturally achieves both doublet-triplet…
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…
In the context of the supersymmetric flipped $SU(5)\otimes U(1)$ GUT model, we have studied in detail the neutrino mass spectrum, obtaining an approximate formula for the corresponding effective three-generation mass matrix. It is found…
We present a viable flipped version of the SO(10) model consistent with the phenomenological requirements of having a non-trivial quark mixing matrix, natural doublet-triplet splitting, and a single pair of light electroweak Higgs doublet…
We discuss baryogenesis using the flipped $SU(5)$ model for lepton mass matrices. We show that the generalized see-saw mechanism in this model can not only provide MSW neutrino mixing suitable for solving the solar neutrino problem, and…
I will present a simple, economic and predictive model of Yukawa structures in the context of a renormalizable SO(10) grandunification. The righthanded neutrino mass is generated radiatively. The fermions have Yukawa couplings with one 10…
We propose a realistic flipped SU(5) model derived from a five-dimensional orbifold SO(10) model. The Standard Model (SM) fermion masses and mixings are explained by combining the traditional Froggatt-Nielsen mechanism with the…
In the first part of this talk it is discussed why observed neutrino oscillations (which suggest the existence of right-handed neutrinos with certain Dirac and Majorana masses) seem to select out the route to higher unification based on the…
Lopsided structure in mass matrices of down quarks and leptons gives a simple explanation for the observed large angles of neutrino mixings. We realize such mass matrices by the Froggatt-Nielsen mechanism in the framework of supersymmetric…
We analyse the fermion masses and mixings in the flipped SU(5) model. The fermion mass matrices are evolved from the GUT scale down to $m_W$ by solving the renormalization group equations for the Yukawa couplings. The constraints imposed by…
In this talk, we propose a GUT scenario in which doublet-triplet splitting is naturally realized in SO(10) unification using the Dimopoulos-Wilczek mechanism and the realistic mass matrices of quarks and leptons are obtained in a simple…
In this Lecture we first review the basic properties that make flipped SU(5) a very economical and well motivated unified model, including some recent developments regarding the prediction for $\alpha_s$ and new implications for proton…
We analyze the possible magnitude of the supersymmetric contribution to $g_\mu - 2$ in a flipped SU(5) GUT model. Unlike other GUT models which are severely constrained by universality relations, in flipped SU(5) the U(1) gaugino mass and…
A fermion mass matrix ansatz is proposed in the context of Grand Unified Supersymmetric Theories (GUTs). The fermion mass matrices are evolved down to the electroweak scale by solving the renormalization group equations for the gauge and…