Related papers: On a mechanism realizing quark mass hierarchy
We consider the maximal U(3) horizontal scheme as a handle on fermion masses and mixings. In particular, we attempt to explain the large top Yukawa coupling and the masses and mixing in the two heaviest generations. A simple model is…
We analyze the structure of quark and lepton mass matrices under the hypothesis that they are determined from a minimum principle applied to a generic potential invariant under the $\left[SU(3)\right]^5\otimes \mathcal O(3)$ flavor…
We present a new solution to the strong CP problem in which the imaginary component of the up quark mass, $\mathcal{I}[m_u]$, acquires a tiny, but non-vanishing value. This is achieved via a Dirac seesaw mechanism, which is also responsible…
We discuss the mass splitting between the the top and bottom quarks in a technicolor scenario. The model proposed here contains a left-right electroweak gauge group. An extended technicolor group and mirror fermions are introduced. The…
The mass-generation mechanism is the most urgent problem of the modern particle physics. The discovery and study of the Higgs boson with the Large Hadron Collider at CERN are the highest priority steps to solve the problem. In this paper,…
The possibility that the mass hierarchy is intimately associated with the compositeness level of the matters is proposed in supersymmetric gauge theory. This implies, for instance, that the preons constituting top quark consists of the…
Using renormalization group techniques, we examine several interesting relations among masses and mixing angles of quarks and leptons in the Standard Model. We extend the analysis to the minimal supersymmetric extension to determine its…
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…
A simple breaking of the subnuclear democracy among the quarks leads to a mixing between the second and the third family, in agreement with observation. Introducing the mixing between the first and the second family, one finds an…
We build on a recent paper by Grinstein, Redi and Villadoro, where a see-saw like mechanism for quark masses was derived in the context of spontaneously broken gauged flavour symmetries. The see-saw mechanism is induced by heavy Dirac…
The mechanism of elementary particle mass generation is a fundamental issue of physics. While cardinal progress has recently been achieved in the case of leptons and current quarks through the Brout-Engler-Higgs mechanism, this issue is at…
We present a generalization of a model where the right-handed up-type quarks serve as messengers for neutrino mass generation and as a portal for dark matter. Within this framework the Standard Model is extended with a single Majorana…
We review some approaches to the quark-lepton mass problem. The ideas of mass-protection and approximate chiral flavour symmetries as a framework for resolving the mass hierarchy problem are presented. Dynamical calculations of the top…
Several phenomenological features of fermion masses and mixings can be accounted for by a simple model for fermion mass matrices, which suggests an underlying U(2) horizontal symmetry. In this context, it is also proposed how an approximate…
A mechanism for generating massive but naturally light Dirac neutrinos is proposed. It involves composite Higgs within the standard model as well as some new interaction beyond the standard model. According to this scenario, a neutrino mass…
In little higgs models a collective symmetry prevents the higgs from acquiring a quadratically divergent mass at one loop. By considering first the littlest higgs model we show that this requires a fine tuning: the couplings in the model…
A seesaw mass matrix model is reviewed as a unification model of quark and lepton mass matrices. The model can understand why top-quark mass m_t is so singularly enhanced compared with other quark masses, especially, why m_t >> m_b in…
We incorporate clockwork mechanism into the Standard Model flavour sector and show that the observed pattern of fermion masses and mixing can be obtained without any unnaturally small or large parameter in the fundamental theory. By…
An extension of the Standard Model (SM) is studied in which two right-handed (RH) neutrinos per generation are incorporated, but considering the hypothesis of the symmetry of lepton and quark contents in order to deprive the number of RH…
We present a framework to generate the quark mass hierarchies and mixing angles by extending the Standard Model with one extra Higgs doublet. The charm and strange quark masses are generated by small quantum effects, thus explaining the…