Related papers: Electroweak limits on physics beyond the Standard …
We elaborate on a recently suggested effective Lagrangian for charged-current and neutral-current electroweak interactions which in comparison with the standard electroweak theory contains three free parameters $\Delta x, \Delta y$,…
These lectures describe why one believes there is physics beyond the Standard Model and review the expectations of three alternative explanations for the Fermi scale. After examining constraints and hints for beyond the Standard Model…
Using a manifestly gauge-invariant approach we show that the set of low-energy constants in the electroweak chiral Lagrangian currently used in the literature is redundant. In particular, by employing the equations of motion for the gauge…
Standard theories of electroweak interactions are based on the concept of a gauge symmetry broken by the Higgs mechanism. If they are placed in an environment with a sufficiently high temperature, the symmetry gets restored. It turns out…
Electroweak symmetry can be naturally broken by observed quark and gauge fields in various extra-dimensional configurations. No new {\it fundamental} fields are required below the quantum gravitational scale ($\sim$ 10 - 100 TeV). We…
Using effective field theory methods, we integrate out the standard model Higgs boson to one loop and represent its non-decoupling effects by a set of gauge invariant effective operators of the electroweak chiral Lagrangian. We briefly…
1. Introduction 2. Status of the Data 3. Precision Electroweak Data and the Standard Model 4. A More General Analysis of Electroweak Data 4.1 Basic Definitions and Results 4.2 Experimental Determination of the Epsilon Variables 4.3…
Strong rescattering corrections to one-loop contributions to the parameters of the standard electroweak model are considered.
Effective Lagrangians can be used to parametrize the effects of physics beyond the standard model. Assuming the complete theory is a gauge theory, we determine which effective operators may be generated at tree level, and which are only…
We know that demanding $SU(2)_L\times U(1)_Y$ gauge symmetry of Lagrangian is a "sufficient" condition to describe electroweak interactions, however, in this paper, we have tried to find whether it's a "necessary" condition or not. We have…
This study investigates the electroweak baryogenesis (EWBG) in the real singlet extension of the Standard Model (SM), including dimension-six operators, which couple the Higgs boson to a real singlet scalar field. We show that the…
If neutrinos are Dirac particles and, as suggested by the so far null LHC results, any new physics lies at energies well above the electroweak scale, the Standard Model effective field theory has to be extended with operators involving the…
We discuss properties of QCD with variable and large $N_c$, taking into account electroweak interactions; i.e., we analyze the generalization of the standard model based on the gauge group $G={\rm SU}(N_c) \times {\rm SU(2)}_L \times {\rm…
We report the results of the global electroweak fit, with emphasis on the most recent results which served as input of the fit. The output of the fit sets also limits on the Standard Model Higgs mass.
Electroweak Baryogenesis is a particularly attractive theoretical scenario, since it relies on physics which can be tested at present high energy collider facilities. Within the Standard Model, it has been shown that the requirement of…
Using a chiral Lagrangian we show that strongly interacting models of electroweak symmetry breaking are not in conflict with precision data. Such models, like Technicolor, need not lead to a heavy Higgs-like signal. Furthermore, the allowed…
We refine our recent analysis of the electroweak precision data at the \PZO\ pole by including the hadronic decay modes of the \PZO. Within the framework of an effective Lagrangian we parametrize $SU(2)$ violation by the additional…
Possible non-standard couplings which could contribute to the t -> b W process are studied based on the effective-Lagrangian approach. The corresponding effective Lagrangian consists of four kinds of dimension-6 effective operators, each of…
We study the low energy limit of Little Higgs models. The method consists in eliminating the heavy fields using their classical equations of motion in the infinite mass limit. After the elimination of the heavy degrees of freedom we can…
We obtain limits on generic vector-like leptons at the TeV scale from electroweak precision tests. These limits are complementary to the ones obtained from lepton flavour violating processes. In general, the quality of the global…