相关论文: Mass generation of the lepton sector

Any of neutrinos similarly to a kind of charged lepton has a non-zero mass responsible as well as for its Coulomb behavior. Such a neutrino can possess both electric charge and vector dipole moment. Their form factors appear, for example,…

In these lecture notes we present mechanisms for the generation of Majorana neutrino masses and lepton mixing. We consider simple extensions of the Standard Model. Apart from a section about radiative mass generation, we put special…

Models with composite singlet neutrinos can give small Majorana or Dirac masses to the active neutrinos. The mechanism is based on the fact that conserved chiral symmetries give massless neutrinos at the renormalizable level. Thus, they…

We study the possibility of generating tiny Dirac neutrino masses at one loop level through the \textit{scotogenic} mechanism such that one of the particles going inside the loop can be a stable cold dark matter (DM) candidate. Majorana…

We propose a novel leptogenesis mechanism with a temperature-dependent coupling between the right-handed neutrino and Standard Model particles. This coupling experiences suppression at high temperatures and becomes sizable when the lepton…

We study neutrino mass generation in models with four chiral families of leptons and quarks and four right handed neutrinos. Generically, in these models there are three different contributions to the light neutrino masses: the usual…

We assume that all quark and lepton $3 \times 3$ mass matrices which appear in the standard model lagrangian (after spontaneous symmetry breaking) with neutrinos treated as Dirac patricles have the triangular form. Such matrices have not…

Amongst the diverse propositions for extra dimensional scenarios, the model of Randall and Sundrum (RS), which offers a solution for the long standing puzzle of the gauge hierarchy problem, has attracted considerable attention from both the…

If the Standard Model particle content is extended by gauge singlet fermions (right-handed neutrinos), active neutrinos generically acquire (Majorana) masses, in agreement with our current understanding of the lepton sector. If the…

We discuss the special class of models where nearly maximal neutrino mixing is produced through the see-saw mechanism, starting from only nearly diagonal matrices for charged leptons, Dirac neutrinos and Majorana right-handed neutrinos.

In a class of two Higgs doublet model, where one Higgs doublet generates masses of quarks and charged leptons whereas the other Higgs doublet with a tiny vacuum expectation value (VEV) generates neutrino Dirac masses, smallness of neutrino…

Probing the origin of neutrino mass by disentangling the seesaw mechanism is one of the central issues of particle physics. We address it in the minimal left-right symmetric model and show how the knowledge of light and heavy neutrino…

Assuming a type-I seesaw mechanism for neutrino mass generation and invoking a baryogengesis via leptogenesis scenario, we consider a reasonable hierarchical structure for Dirac neutrino mass matrix, similar to up-type quark mass matrix.…

We study the generation of neutrino masses in the $SU(3)_W$ electroweak unified theory in $M_4\times S_1/(Z_2\times Z'_2)$ spacetime. By appropriate orbifolding, the bulk symmetry $SU(3)_W$ is broken into $SU(2)_L \times U(1)_Y$ at one of…

The symmetry breaking of left right symmetric model around few TeV range permits the existence of massive right handed neutrinos or gauge bosons. In this work the decay of lightest right handed neutrinos in a class of minimal left right…

We show that Dirac neutrino masses of the right size can arise from the Kahler potential of supergravity. They are proportional to the supersymmetry and the electroweak breaking scales. We find that they have the experimentally observed…

We study leptogenesis in three different realisations of the type Ib seesaw mechanism, where the effective masses of the neutrinos are obtained by the spontaneous symmetry breaking of two different Higgs doublets. In the minimal type Ib…

We investigate the leptogenesis with almost degenerate neutrinos, in the framework of democratic mass matrix, which naturally explains the large mixing angles for neutrino oscillations as well as quark masses and mixing matrix. We find that…

Status of the discrete symmetry approach to explanation of the lepton masses and mixing is summarized in view of recent experimental results, in particular, establishing relatively large 1-3 mixing. The lepton mixing can originate from…

In this talk we show how a natural neutrino mass hierarchy can follow from the type I see-saw mechanism, and a natural neutrino mass degeneracy from the type II see-saw mechanism, where the bi-large mixing angles can arise from either the…