相关论文: The Lepton Sector of a Fourth Generation

Experimental observation of Majorana fermion matter gives a new impetus to the understanding of the Lorentz symmetry and its extension, the geometrical properties of the ambient space-time structure, matter--antimatter symmetry and some new…

We study the generation of small neutrino masses in an extra-dimensional model, where right-handed neutrinos are allowed to propagate in the extra dimension, while the Standard Model particles are confined to a brane. Motivated by the fact…

We replace the Higgs sector of the Standard electroweak gauge model of three fermion families by a horizontal non-vector-like gauge SU(3) quantum flavor dynamics with one parameter. With plausible physical assumptions we suggest that the…

The predicted value of the higgs mass $m_H$ is analyzed assuming the existence of the fourth generation of leptons ($N, E$) and quarks ($U, D$). The steep and flat directions are found in the five-dimensional parameter space: $m_H$, $m_U$,…

It is argued with the help of an illustrative model, that the inter--species hierarchy among the fermion masses and the quark mixing angles can be accommodated naturally in the standard model with (approximate) flavor democracy provided…

In view of the fact that the data on neutrino mixing are still compatible with a situation where Bimaximal mixing is valid in first approximation and it is then corrected by terms of order of the Cabibbo angle, arising from the…

After some general remarks about SU_L(4) electroweak unification, the model is extended to SU_L(4)xU_X(1) to accomodate fractionally charged quarks. The unification scale is expected to be in TeV region. A right-handed Majorana neutrino…

We explore an $A_4$-symmetric flavor based left-right symmetric model with linear seesaw mechanism and study the associated neutrino phenomenology. The framework offers the advantage of studying neutrino mass, non-unitarity effects in…

We study the signatures of minimal lepton flavour violation in a simple Type-III see - saw model in which the flavour scale is given by the new fermion triplet mass and it can be naturally light enough to be produced at the LHC. In this…

We explore calculable models with low-energy supersymmetry where the flavor hierarchy is generated by quark and lepton compositeness, and where the composites emerge from the same sector that dynamically breaks supersymmetry. The observed…

We overview the constraints on the 4th-generation neutrino dark matter candidate and investigate a possible way to make it a viable dark matter candidate. Given the LEP constraints tell us that the 4th-generation neutrino has to be rather…

I review the origin of the lepton asymmetry which is converted to a baryon excess at the electroweak scale. This scenario becomes more attractive if we can relate it to other physical phenomena. For this reason I elaborate on the conditions…

Flavour symmetries have been used to constrain both quark and lepton mixing parameters. In particular, they can be used to completely fix the mixing angles. For the lepton sector, assuming that neutrinos are Majorana particles, we have…

We investigate the phenomenological consequences of lepton mass matrices originated from the family permutation symmetry and its suitable breakings. Adopting the recently proposed new mass matrix for the charged lepton mass matrix and the…

We propose a new scaling ansatz in the neutrino Dirac mass matrix to explain the low energy neutrino oscillations data, baryon number asymmetry and neutrinoless double beta decay. In this work, a full reconstruction of the neutrino Dirac…

We consider tri-bimaximal lepton mixing within low-scale seesaw schemes where light neutrino masses arise from TeV scale physics, potentially accessible at the Large Hadron Collider (LHC). Two examples are considered, based on the A4 flavor…

If the neutrinos are Majorana fermions, there are at least three new, potentially observable CP-odd phases that parameterize CP-invariance violating phenomena. We currently have no information regarding any of them and know that two out of…

The mass term for Majorana neutrinos explicitly violates lepton number. Several authors have used this fact to create a lepton asymmetry in the universe by considering CP violating effects in the one loop self-energy correction for the…

Minimal models exist in which thermal, resonant leptogenesis occurs at the electroweak scale. The effects of individual lepton flavours play a crucial role and allow successful leptogenesis with large couplings between some of the charged…

We study the pair production of fourth generation neutrinos from the decay of an on-shell Higgs produced by gluon fusion. In a fourth generation scenario, the Higgs branching fraction into fourth generation neutrinos may be quite large. In…