Related papers: Electroweak Limits on Non-Universal Z' Bosons
An extension of the Standard Model is presented that leads to the possible existence of new gauge bosons with masses in the range of a few TeV. Due to the fact that their couplings to Standard Model fermions are strongly suppressed, it is…
An extension of the standard model of electro-weak interactions by an extra abelian gauge boson is given, in which the extra gauge boson and the hypercharge gauge boson both couple to an axionic scalar in a form that leads to a Stueckelberg…
We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that 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…
An insightful way of presenting the LHC limits on dijet resonances is the coupling-mass plot for a $Z'$ boson that has flavor-independent quark interactions. This also illustrates the comparison of low-mass LHC sensitivity with constraints…
The seeming violation of universality in the tau lepton coupling to the W boson suggested by LEP II data is studied using an Effective Field Theory (EFT) approach. Within this framework we explore how this feature fits into the current…
We construct extensions of the Standard Model in which the gauge symmetries and supersymmetry prevent the dangerously large effects that may potentially be induced in a supersymmetric standard model by Planck scale physics. These include…
The effects of an extra $Z'$ gauge boson with family nonuniversal fermion couplings on the rare top quark decay $t --> c $gamma$ are first examined in a model independent way and then in the minimal 331 model. It is found that the…
We study the physics potential of the 8 TeV LHC to discover signals of extended gauge models or extra dimensional models whose low energy behavior is well represented by an SU(2) x SU(2) x U(1) electroweak gauge structure. We find that with…
We derive electroweak constraints on the compactification scale of minimal 5-dimensional extensions of the Standard Model, in which all or only some of the SU(2)$_L$ and U(1)$_Y$ gauge fields and Higgs bosons feel the presence of the fifth…
We propose a non-supersymmetric SU(5) model in which only the third family of fermions are unified. The model remedies the non-unification of the three Standard Model couplings in non-supersymmetric SU(5). It also provides a mechanism for…
The fundamental description of nature, beyond the Standard Model (SM), may include heavy neutrinos that mix and thus allow processes in which lepton flavor is not preserved. We investigate the impact of charged currents that couple heavy…
The discrepancies between the measurements of rare (semi-)leptonic $B$ decays and the corresponding Standard Model predictions point convincingly towards the existence of new physics for which a heavy neutral gauge boson ($Z^\prime$) is a…
It is notorious that, contrary to all other precision electroweak data, the forward-backward asymmetry for b quarks $A_{FB}^b$ measured in Z decays at LEP1 is nearly three standard deviations away from the predicted value in the Standard…
The motivations for studying dynamical scenarios of electroweak and flavor symmetry breaking are reviewed and the latest ideas, especially topcolor-assisted technicolor, are summarized. Several technicolor signatures at the Tevatron and…
We analyze constraints on a class of extended technicolor (ETC) models from neutral flavor-changing processes induced by (dimension-six) four-fermion operators. The ETC gauge group is taken to commute with the standard-model gauge group.…
A U(1)' or Z' is generic in many scenarios of physics beyond the Standard Model, such as string theory compactifications, GUTs, extra-dimensions, compositeness, dynamical electroweak symmetry breaking, dark-sector models, etc. We study the…
The presence of an extra dimension of size R \approx TeV^{-1} introduces a tower of Kaluza-Klein gauge boson excitations that affects the standard model (SM) relations between electroweak observables. The mixing of the W and Z bosons with…
New neutral heavy gauge bosons ($Z^\prime$) are predicted within many extensions of the Standard Model. While in case they couple to quarks the LHC bounds are very stringent, leptophilic $Z^\prime$ bosons (even with sizable couplings) can…
In the context of topcolor-assisted techicolor($TC2$) models, we investigate the feasibility of detecting the non-universal gauge boson $Z^{'}$ in the future high-energy linear $e^{+}e^{-}$ collider($LC$) experiments by performing…