相关论文: Limitations of B-meson mixing bounds on technicolo…
We argue that extended technicolor augmented with topcolor requires that all mixing between the third and the first two quark generations resides in the mixing matrix of left-handed down quarks. Then, the anti-B_d--B_d mixing that occurs in…
Using precision electroweak data, we put limits on ``natural'' top-color assisted technicolor models. Generically the new $U(1)$ gauge bosons in these models must have masses larger than roughly 2 TeV, although in certain (seemingly…
Many types of physics beyond the standard model include an extended electroweak gauge group. If these extensions are associated with flavor symmetry breaking, the gauge interactions will not be flavor-universal. In this note we update the…
We propose and discuss the phenomenology of a Topcolor-assisted Technicolor (TC2) model with a flavor-universal hypercharge sector. After discussing the symmetry breaking pattern and low-energy effective Lagrangian, we examine various…
In topcolor-assisted technicolor models (TC2) the hitherto unconstrained lepton flavor mixing induced by the new gauge boson $Z'$ will lead to the lepton flavor violating productions of $\tau\bar \mu$, $\tau\bar e$ and $\mu\bar e$ in…
In the context of flavor-universal topcolor-assisted technicolor (TC2) models, we calculate the lepton flavor violating (LFV) $Z\to l_il_j$ decays. We find that the extra U(1) gauge boson $Z^{\prime}$ can give significant contributions to…
We suggest a criterion to minimize the amount of fine-tuning in a composite Higgs model. The paradigm of this type of model is the top-condensate model of Bardeen, Hill and Lindner (BHL). Although "minimally fine-tuned", this model failed…
I propose a resolution of the strong CP problem of quarks based on vacuum alignment in theories of dynamically broken electroweak and flavor symmetries. Mixing in the neutral B and K--meson systems is used to restrict the form of quark mass…
New strong gauge interactions remain a viable source for the electroweak symmetry breaking. However, addressing the generation of fermion masses remains a challenge. A basic observable which provides stringent constraints on the flavor…
Recent study on the charged top-pion correction to R_b shows that it is negative and large, so that the precision experimental value of R_b gives rise to a severe constraint on the topcolor-assisted technicolor models such that the top-pion…
We consider the lepton-flavor violating(LFV) processes $l_{i}\to l_{j}\gamma$ in the framework of topcolor assisted technicolor(TC2) models. We find that the new gauge boson $Z^{\prime}$ predicted by TC2 models can give significantly…
We calculate the rates for lepton number violating processes via the exchange of the Z' boson occuring in top-color assisted technicolor. The current experimental limits on muon electron conversion in Ti nuclei allow for a mass of the new…
The trilinear self-coupling of the Higgs boson, in a theory in which this boson is composite, is compared to the experimental bound of this quantity obtained by the CMS experiment. In the case of a model where technicolor (TC) is coupled to…
Certain string-inspired Z' models have non-universal interactions to three families of fermions and induced tree-level flavor-changing couplings. We use recent results on B_s-anti-B_s mixing to constrain the size of the flavor-changing…
We consider the phenomenology of models in which electroweak symmetry breaking is triggered by new strong dynamics affecting the third generation and is transmitted to the light fermions via a fundamental Higgs doublet. While similar in…
We tested several models in which the Standard Model (SM) gauge group is extended by an additional U(1) gauge symmetry, against available electroweak precision data to impose limits on the mass of the neutral Z' boson, M_Z', predicted in…
We discuss and estimate the contributions of the new particles predicted by topcolor assisted technicolor(TC2) models to the muon anomalous magnetic moment $a_{\mu}$. Our results show that the contributions of Pseudo Goldstone bosons are…
We examine experimental constraints on scharm-stop flavor mixing in the minimal supersymmetric standard model, which arise from the experimental bounds on squark and Higgs boson masses, the precision measurements of W-boson mass and the…
In the context of topcolor-assisted technicolor (TC2) models, we examine the flavor changing (FC) Z decay $Z\to b\bar{s}(\bar{b}s)$ and calculate the contributions of the new particles predicted by TC2 models to the branching ratio Br($Z\to…
The constraints on the mixing angles of the standard fermions with new heavy particles that can appear in many extensions of the electroweak theory are reviewed. Some emphasis is put in distinguishing the effects of a mixing with new states…