Related papers: Four-Fermion Dynamics and Fermion Masses
To a first approximation, the quark mixing matrix has $\theta^q_{13} = \theta^q_{23} = 0$, whereas the lepton mixing matrix has $\theta^l_{23} = \pi/4$. We show how this structure may be understood if the family symmetry is $Q_8$, the…
We consider a new approach to fermion masses and mixings in which no special "horizontal" dynamics is invoked to account for the hierarchical pattern of charged fermion masses and for the peculiar features of neutrino masses. The hierarchy…
We present models in which the observed fermion masses and mixings are generated by dynamically localizing the three generations of matter in a flat compact extra dimension. We first construct models assuming the hierarchy problem is…
We discuss a test of the Standard Model fermion mass origin in models of dynamical electroweak symmetry breaking. The couplings of composite pseudoscalar resonances to top quarks allow to distinguish high-scale Extended-Technicolor-type…
It is investigated that a dynamical mechanism to generate a low mass fermion in Randall-Sundrum (RS) background. We consider a five-dimensional four- fermion interaction model with two kinds of bulk fermion fields and take all the mass…
A suggestive phenomenological relation is found among the lepton and quark masses which suggests a new insight into the problem of generations and also gives a prediction for the top quark mass in agreement with the range of values which is…
We present a supersymmetric model of fermion masses with SU(4)*SU(2)^2*U(1)_X gauge group with matter in fundamental and antisymmetric tensor representations only. The up, down, charged lepton and neutrino Yukawa matrices are distinguished…
We provide a unified description of fermion masses and mixing angles in the framework of a supersymmetric grand unified SO(10) model with anarchic Yukawa couplings of order unity. The space-time is five dimensional and the extra flat…
We introduce a new parametrization of the MNS lepton mixing matrix which separates the hierarchical Grand Unified relations among quarks and leptons. We argue that one large angle stems from the charged leptons, the other from the seesaw…
We address the question, how general is the gauge sector in extra-dimensional models which explain hierarchies of masses and mixings of quarks, charged leptons and neutrinos in terms of a single family of multidimensional fermions. We give…
We propose a class of theories to generate quark and lepton mass matrices where the scale of new physics is at the TeV scale, without inducing the large flavor and CP violating processes that are often thought to relegate the origin of…
The new quarks of a fourth family are being pushed into the strongly interacting regime due to the lower limits on their masses. The theoretical basis and experimental implications of such quarks are compared with exotic quarks.
Motivated by the Super-Kamiokande data, we revisit models with U(1) symmetries and discuss the origin of neutrino masses and mixings in such theories. We show that, in models with just three light neutrinos and a hierarchy of neutrino…
We consider fermions propagating in the bulk of the geometry found by deforming AdS, in 5 dimensions, via the back reaction of a scalar field upon the metric. This space is AdS for r asymptotically large (in the UV) but goes through a…
Effects of four-Fermi-type new interactions are studied in top-quark pair production and their subsequent decays at future e^+e^- colliders. Secondary-lepton-energy distributions are calculated for arbitrary longitudinal beam polarizations.…
We explore a scenarios where topcolor-like dynamics operates in the presence of fourth generation matter fields. Using the Minimal Walking Technicolor as a concrete basis for model building, we construct explicit models and confront them…
We present a novel mechanism for generating gauge-invariant fermion masses through global anomalies at the three loop level. In a gauge theory, global anomalies are triggered by the possible existence of scalar or pseudoscalar states and…
We consider a model in which dark matter is stable as it is charged under a Z2 symmetry that is residual after an A4 flavour symmetry is broken. We consider the possibility to generate the quark masses by charging the quarks appropriately…
A new mechanism for generating neutrino masses without a high-energy mass scale is proposed. The mechanism needs a fundamental mass scale M in the 100-1000 TeV region and a minimal field content beyond the Standard Model one containing a…
We review some recent work on nonperturbative properties of fermions and connections with chiral gauge theories. In particular, we consider one of the ultimate goals of this program: the understanding of the actual fermion mass spectrum. It…