Related papers: Hints of Dynamical Symmetry Breaking?
A possible extension of the Standard Model to include lepton number as local gauge symmetry is investigated. In such a model, anomalies are canceled by two extra fermions doublet. After leptonic gauge symmetry spontaneously broken, three…
We study a hybrid model in which the Technicolor and fundamental heavy scalars live together. We concern extreme case, where electroweak symmetry breaking (EWSB) comes almost entirely from the strong dynamics of Technicolor, but the masses…
The Principle of Naturalness of small parameters of a theory is reviewed. While quantum field theories constructed from gauge fields and fermions only are natural, those containing elementary scalar fields are not. In particular the Higgs…
Our contribution sets out to investigate the phenomenology of a gauge model based on an $SU_{L}(2) \times U_{R}(1)_{Q} \times U(1)_{Q'}$-symmetry group. The model can accommodate, through its symmetry-breaking pattern, a candidate to a…
New strong dynamics at the energy scale ~ 1 TeV is an attractive and elegant theoretical ansatz for the origin of electroweak symmetry breaking. We review here the theoretical models for strong dynamics, particularly, technicolor theories…
We survey the phenomenological constraints on abelian gauge bosons having masses in the MeV to multi-GeV mass range (using precision electroweak measurements, neutrino-electron and neutrino-nucleon scattering, electron and muon anomalous…
A new $U(1)$ gauge boson coupling predominantly to the third family has been considered in connection with recent LEP data. We consider another likely consequence of such a gauge boson, a greatly enhanced $b$ quark decay mode, $b \to s…
We propose a dynamical model with a (2 + 1)-structure of composite Higgs doublets: two nearly degenerate composites of the fourth family quarks t' and b', $\Phi_{t^{\prime}} \sim \bar{t^{\prime}}_{R}(t^{\prime},b^{\prime})_L$ and…
We review recent works on supersymmetry breaking and gauge mediation. We survey our current understanding of dynamical supersymmetry breaking mechanisms and describe new model building tools using duality, meta-stability, and stringy…
The possibility of dynamical electroweak symmetry breaking by strong coupling gauge interaction in models with D-branes in String Theory is examined. Instead of elementary scalar Higgs doublet fields, the gauge symmetry with strong coupling…
In this talk I discuss theories of dynamical electroweak symmetry breaking, with emphasis on the implications of a heavy top-quark on the weak-interaction $\rho$ parameter.
A massive gauge boson coupling to the third family but not lighter families mixes with the $Z$. The $Z$ partial width to $b\overline{b}$ increases, the $\tau$ asymmetry parameter increases, the invisible width of the $Z$ decreases, and…
Indirect precision data are used to constrain the masses of possible extra Z^prime bosons and their mixings with the ordinary Z. We study a variety of Z^prime bosons as they appear in E_6 and left-right unification models, the sequential Z…
Within the framework of a Beyond Standard Model (BSM) with a local $SU(3)$ family symmetry, we report an updated fit of parameters which account for the known spectrum of quarks and charged lepton masses and the quark mixing in a $4\times…
We propose an effective left-right-right-left model with a parity breaking scale around a few TeV. One of the main achievements of the model is that the mirror fermions as well as the mirror gauge sector simultaneously could be at TeV…
We investigate symmetry breaking patterns from replicated gauge groups which generate anomaly-free and family-dependent U(1) symmetries. We discuss the extent to which these symmetries can explain the observed hierarchies of fermion masses…
We review dynamical mass generation in three and four dimensional Ableian gauge theories. The basic approach analyzed here is to solve Schwinger-Dyson equations in some approximations. In both cases, the coupling has to be larger than a…
Fermion mass models usually contain a horizontal symmetry and therefore fail to predict the exponential mass spectrum of the Standard Model in a natural way. In dynamical symmetry breaking there are different concepts to introduce a fermion…
Experiment shows that the top quark is far heavier than the other elementary fermions. This finding has stimulated research on theories of electroweak and flavor symmetry breaking that include physics beyond the standard model. Efforts to…
The mass spectra of the standard model particles are reproduced in the $SO(11)$ gauge-Higgs grand unification in the six-dimensional warped space without introducing exotic light fermions. Light neutrino masses are explained by the…