Related papers: A Minimal Four-Family Supergravity Model
We give a new mechanism for generating very small, and almost degenerate, neutrino masses, without resorting to the see-saw mechanism or unnatural small Yukawa couplings. It requires the existence of at least 4 families with an almost…
Fermion masses and mixing angles including that of neutrinos are studied in a model with symmetry group SUSY $SO(10)\times \Delta (48) \times U(1)$. Universality of Yukawa coupling of superfields is assumed. The resulting texture of mass…
We analyze the parametric space of the constrained minimal supersymmetric standard model (CMSSM) with mu>0 supplemented by a generalized asymptotic Yukawa coupling quasi-unification condition which yields acceptable masses for the fermions…
We study a supersymmetric extension of the vector-like lepton scenario, such that the vacuum instability induced by large lepton Yukawa couplings is lifted by the presence of superpartners at or below the TeV scale. In order to preserve the…
We discuss the charged and neutral fermion masses and mixings in a supersymmetric SO(10) model with a minimal Higgs sector consisting of the multiplets $10_H$, $45_H$, and $16_H + \overline{16}_H$. In addition to the renormalizable Yukawa…
If new sequential leptons $E^\pm$ and $N^0$ exist, the LEP bound implies $m_E$, $m_N > M_Z/2$. The heaviness of the neutral lepton breaks away from the pattern of the first three generations. The minimal model is to have 4 left-handed…
In a recent paper, a minimal supersymmetric (SUSY) SO(10)xS_4 based unified model of flavor for quarks and leptons was proposed with two 10 and one 126 contributing to fermion masses. An important aspect of this model is that Yukawa…
We are proposing a new way of describing families of quarks and leptons, using the approach unifying all the internal degrees of freedom, proposed by one of us. Spinors, living in d(=1+13)-dimensional space, carry in this approach only the…
We consider the possibility that a massive fourth family neutrino, predicted by a recently proposed minimal technicolor theory, could be the source of the dark matter in the universe. The model has two techniflavors in the adjoint…
We study the scalar potential and the mass spectrum of the supersymmetric extension of a three-family model based on the local gauge group $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$, with anomalies canceled among the three families in a…
Much heavier sfermions of the first-two generations than the other superparticles provide a natural explanation for the flavor and CP problems in the supersymmetric standard model (SUSY SM). However, the heavy sfermions may drive the mass…
The spin-charge-family theory predicts before the electroweak break four - rather than the observed three - massless families of quarks and leptons. The 4 x 4 mass matrices of all the family members demonstrate in this theory the same…
The methodology of the heterotic mini-landscape attempts to zero in on phenomenologically viable corners of the string landscape where the effective low energy theory is the Minimal Supersymmetric Standard Model with localized grand…
The spin-charge-family theory, which is a kind of the Kaluza-Klein theories but with fermions carrying two kinds of spins (no charges), offers the explanation for all the assumptions of the standard model, with the origin of families, the…
We consider 4D weak scale theories arising from 5D supersymmetric (SUSY) theories with maximal Scherk-Schwarz breaking at a Kaluza-Klein (KK) scale of several TeV. Many of the problems of conventional SUSY are avoided. Apart from 3rd family…
We consider extensions of the standard model with fourth generation fermions (SM4) in which extra symmetries are introduced such that the transitions between the fourth generation fermions and the ones in the first three generations are…
We study the effect of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same…
We study the \mu \to e \gamma decay in the Z_3-invariant next-to-minimal supersymmetric (SUSY) Standard Model (NMSSM) with superheavy right-handed neutrinos. We assume that the soft SUSY breaking parameters are generated at the GUT scale,…
We examine the infra-red structure of soft supersymmetry breaking masses of the squarks and sleptons in supersymmetric (SUSY) strong unification schemes where $\alpha_{GUT}\sim 0.2-1$. We show that combinations of soft masses approach fixed…
Grand unified theories often predict unification of Yukawa couplings (e.g., $h_{b} = h_{\tau}$), and thus certain relations among fermion masses. The latter can distinguish these from models that predict only coupling constant unification.…