相关论文: The Fourth SM Family Neutrino at Future Linear Col…

The necessity of the fourth family follows from the SM basics. According to flavor democracy the Dirac masses of the fourth SM family fermions are almost equal with preferable value 450 GeV, which corresponds to common (for all fundamental…

The potential of $\mu ^{+}\mu ^{-}$ colliders to investigate the fourth SM family fermions predicted by flavour democracy has been analyzed. It is shown that muon colliders are advantageous for both pair production of fourth family fermions…

The flavor democracy hypothesis was introduced in seventies taking in mind three Standard Model (SM) families. Later, this idea was disfavored by the large value of the t-quark mass. In nineties the hypothesis was revisited assuming that…

The flavor democracy favors the existence of the nearly degenerate fourth SM family, whereas the fifth SM family is disfavored both by the mass phenomenology and precision tests of the Standard Model. The multi-hundreds GeV fourth family…

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…

We propose a predictive model based on the $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ gauge group supplemented by the $A_{4}\otimes Z_{3}\otimes Z_{4}\otimes Z_{6}\otimes Z_{16}$ discrete group, which successfully describes the SM fermion…

In the Standard Model, three discovered generations of leptons and quarks are known to date. However, speculations about existence of next generations have a strong foothold. In this study, we sequentially extrapolate the Standard Model to…

There are strong arguments favoring the Flavor Democracy hypothesis (or the Democratic Mass Matrix approach) within the Standard Model framework. However, the large mass of the top quark ($m_t >> m_b, m_\tau$) poses an obstacle to the…

Existence of the fourth family follows from the basics of the Standard Model and the actual mass spectrum of the third family fermions. We discuss possible manifestations of the fourth SM family at existing and future colliders. The LHC and…

Mass pattern of the SM fermions is one of the most important mysterious in particle physics. Flavor Democracy could shed light on this mystery. Addition of isosinglet quark and isosinglet lepton give opportunity to obtain masses of charged…

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 continue our previous determination of the masses of the sequential fourth generation quarks in an extension of the Standard Model, and predict the mass $m_4$ ($m_L$) of the fourth generation neutrino $\nu_4$ (charged lepton $L$) by…

On the basis of a seesaw-type mass matrix model for quarks and leptons, $M_f \simeq m_L M_F^{-1} m_R$, where $m_L\propto m_R$ are universal for $f=u,d,\nu$ and $e$ (up-quark-, down-quark-, neutrino- and charged lepton-sectors), and $M_F$ is…

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…

Based on the "democratic" universal seesaw model, where mass matrices $M_f$ of quarks and leptons f_i (f=u,d,\nu,e; i=1,2,3) are given by a seesaw form M_f\simeq -m_L M_F^{-1} m_R, and m_L and m_R are universal for all the fermion sectors,…

In this paper, we move from a "proof of concept" to challenging predictions in a flavour model emerging from a single fermion family in six dimensions (6-D) with the two extra dimensions compactified on a sphere. The most striking…

This is a review article about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing…

We construct a low-scale seesaw model to generate the masses of active neutrinos based on $S_4$ flavor symmetry supplemented by the $Z_2 \times Z_3 \times Z_4 \times Z_{14}\times U(1)_L$ group, capable of reproducing the low energy Standard…

Given the eventuality of neutrino and muon factories in the foreseeable future, all possible 2-to-2 processes involving two neutrinos, whether Dirac or Majorana ones, and two charged fermions are considered on the basis of the most general…

Nonzero neutrino masses imply the existence of degrees of freedom and interactions beyond those in the Standard Model. A powerful indicator of what these might be is the nature of the massive neutrinos: Dirac fermions versus Majorana…