Related papers: $S_4$ symmetric four-generation models for charged…
We consider a generic type of leptogenesis model which can successfully produce the correct value of the observed baryon number to entropy ratio. The main feature of this model is that it is a simple TeV scale model, a scale accessible in…
The four-lepton final state, rare in standard model processes, is an attractive channel for new physics searches at the LHC. In supersymmetry (SUSY), charged leptons may arise from R-Parity conserving (RPC) cascade decays of SUSY particles…
We discuss a model for the lepton sector based on the seesaw mechanism and on a $D_4$ family symmetry. The model predicts the mixing angle $\theta_{13}$ to vanish. The solar mixing angle $\theta_{12}$ is free--it will in general be large if…
We consider Koide's equation for charged leptons jointly with hypotheses implied in the ancient Dual Quark-Gluon model. The focus is to motivate the possibility of a supersymmetric framework akin to the one of D=11 maximal supergravity.
We compute the mass spectrum of the fermionic sector of the Dirac-Kaehler extension of the SM (DK-SM) by showing that there exists a Bogoliubov transformation that transforms the DK-SM into a flavor U(4) extension of the SM (SM-4) with a…
We investigate the single and pair production of new heavy leptons via string inspired $E_{6}$ model at future linear colliders. Signal and corresponding backgrounds for these leptons are studied. We have found that single production of…
It has been recently claimed that the symmetry group S4 yields to the Tri-bimaximal neutrino mixing in a "natural" way from the group theory point of view. Approving of this feature as an indication, we build a supersymmetric model of…
We construct a 3-3-1 model based on family symmetry S_4 responsible for the neutrino and quark masses. The tribimaximal neutrino mixing and the diagonal quark mixing have been obtained. The new lepton charge \mathcal{L} related to the…
We study leptogenesis in supersymmetric SO(10) models with a left-right symmetric seesaw mechanism, including flavour effects and the contribution of the next-to-lightest right-handed neutrino. Assuming M_D = M_u and hierarchical light…
A heavy triplet of leptons $(\Sigma^+, \Sigma^0, \Sigma^-)_R$ per family is proposed as the possible anchor of a small seesaw neutrino mass. A new U(1) gauge symmetry is then also possible, and the associated gauge boson $X$ may be…
In the spin-charge-family theory four massless families of quarks and leptons before the electroweak break are predicted. Mass matrices of all the family members demonstrate in this proposal the same symmetry, determined by the family…
The charged lepton masses obey to high precision the so-called Koide relation. We propose a generalization of this relation to quarks. It includes up and down quarks of the three generations and is numerically reasonably close to the Koide…
We produce five flavour models for the lepton sector. All five models fit perfectly well---at the one-sigma level---the existing data on the neutrino mass-squared differences and on the lepton mixing angles. The models are based on the…
We propose a realistic A4 extension of the Standard Model involving a particular quark-lepton mass relation, namely that the ratio of the third family mass to the geometric mean of the first and second family masses are equal for down-type…
We consider the effects of a fourth generation of chiral fermions within the MSSM. Such a model offers the possibility of having the lightest neutral Higgs boson significantly heavier than in the three generation MSSM. The model is highly…
In the Minimal Supersymmetric Standard Model (MSSM) with three generations of fermions, there is a stringent upper bound on the mass of the lightest neutral Higgs h, and the mass of the charged Higgs H^+, must be close (within tens of GeV)…
In this paper, we analyse resonant leptogenesis in a low scale inverse seesaw model with $A_4$ flavor symmetry, in a model we explored earlier to explain light neutrino masses and mixings, and also charged lepton flavor violating decay…
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…
A sequential fourth generation of quarks and leptons is allowed by precision electroweak constraints if the mass splitting between the heavy quarks is between 50 and 80 GeV. Although heavy quarks can be easily detected at the LHC, it is…
A new supersymmetric gauge model is proposed with particle content chosen only from the 27 and 27* representations of E_6. The gauge symmetry SU(3) X SU(2)_L X SU(2)_R X U(1) is realized at the TeV energy scale and the gauge couplings…