Related papers: Three sterile neutrinos in E6
A simple model to accomodate light sterile neutrinos naturally with large mixing with the usual neutrinos has been proposed. The standard model gauge group is extended to include an $SU(2)_S$ gauge symmetry. Heavy triplet higgs scalars give…
Neutrinos can have naturally small Dirac masses if the Standard Model singlet right-handed neutrinos are light composite fermions. Theories which produce light composite fermions typically generate many of them, three of which can marry the…
The simplest scenario for the three known light neutrinos that fits the solar and atmospheric neutrino deficit and a mixed dark matter (MDM) picture of the universe requires them to be highly degenerate with $m_{\nu} \sim$ 1 - 2 eV. We…
Assuming that neutrinos are not Majorana fermions and the right handed Dirac neutrino does not exist, we propose a model in which the second and the third generations of the leptons are composites, while the first generation is fundamental.…
We consider the simplest extension of the standard electroweak model by one sterile neutrino that allows for neutrino masses and mixing. We find that its leptonic sector contains much less free physical parameters than previously realized.…
It is shown that it is possible to create successful models of flavor for both quarks and leptons using the discrete non-abelian group $T^{\prime}$ by itself. Two simple realizations are presented that can be used as the starting point for…
The electroweak model, which lepton sector correspond to the contracted gauge group $ SU(2;j)\times U(1), j \rightarrow 0 $, whereas boson and quark sectors are standard one, is suggested. This model describe in a natural manner why…
Quarks, leptons and heavy vector bosons are suggested to be composed of stable spin-1/2 preons, existing in three flavours, combined according to simple rules. Straightforward consequences of an SU(3) preon-flavour symmetry are the…
We construct a simple SO(10) SUSY GUT with $D_3$ family symmetry and low energy R parity. The model describes fermion mass matrices with 14 parameters and gives excellent fits to 20 observable masses and mixing angles in both quark and…
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…
Model-building issues raised by the prospect of light sterile neutrinos are discussed in a pedagogical way. I first review the na\"{\i}ve proposal that sterile neutrinos be identified with ``right handed neutrinos''. A critical discussion…
We provide a minimal alternative gauged U(1)$_{\rm B-L}$ model in which three right-handed neutrinos with charges of (5,-4,-4) and only one B-L Higgs field with charge 1 are introduced. Consistent active neutrino masses and mixings can be…
Light sterile neutrinos of mass about an eV with mixing $\tilde U_{ls}$ of a few percent to active neutrinos may solve some anomalies shown in experimental data related to neutrino oscillation. How to have light sterile neutrinos is one of…
We present a concise review of the recent important experimental developments on neutrino mixing (hints for sterile neutrinos, large $\theta_{13}$, possible non maximal $\theta_{23}$, approaching sensitivity on $\delta_{CP}$) and their…
Neutrinos, being the only fermions in the Standard Model of Particle Physics that do not possess electromagnetic or color charges, have the unique opportunity to communicate with fermions outside the Standard Model through mass mixing. Such…
A discrete symmetry S3 easily explains all neutrino data. However it is not obvious the embedding of S3 in GUT where all fermions live in the same representation. We show that embedding S3 in E6 it is possible to make distinction between…
Conventional superstring derived E$_6$ models can accommodate small neutrino masses if a discrete symmetry is imposed which forbids tree level Dirac neutrino masses but allows for radiative mass generation. Since the only possible…
We consider an $SU(3)_L\otimes U(1)_N$ model for the electroweak interactions which includes extra charged leptons which do not mix with the known leptons. These new leptons couple to $Z^0$ only through vector currents. We consider…
The existence of extra chiral generations with all fermions heavier than $M_Z$ is strongly disfavored by the precision electroweak data. The exclusion of one additional generation of heavy fermions in SUSY extension of Standard Model is…
A grand unified model based on SU(5) and supersymmetry is presented. Pairs of superfields belonging to 15 and 15* representations are newly introduced, while gauge coupling unification is satisfied. Improper mass relations in the minimal…