Related papers: Renormalization Group Constraints on New Top Inter…
The study of the top quark's properties is an important part of the LHC programme. In earlier work, we have studied the rare decay $t \to b \bar b c$, using effective operators to capture the effects of physics beyond the Standard Model.…
Measurement of the Yukawa interaction between the top quark and the Higgs boson should be useful to clarify the mechanism of fermion mass generation. We discuss the impact of non-standard interactions characterized by dimension-six…
In this talk, using deconstruction, we analyze the form of the corrections to the electroweak interactions in a large class of ``Higgsless'' models of electroweak symmetry breaking, allowing for arbitrary 5-D geometry, position-dependent…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results obtained at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
We update our previous work on an analysis of the electroweak data by including new and partly preliminary data available up to the 1996 summer conferences. The new results on the Z partial decay widths into b and c hadrons now offer a…
We consider direct bounds on the coefficients of higher dimensional top quark dipole operators from their contributions to anomalous top couplings that affect some related processes at the LHC. Several observables are studied. In…
In this work, we investigate the collider constraints on effective interactions between Dark Matter (DM) particles and electroweak gauge bosons in a systematic way. We consider the simplified models in which scalar or Dirac fermion DM…
We present sensitivity limits on the coefficients of a dimension-6 effective Lagrangian that parametrizes the possible effects of new physics beyond the Standard Model. Our results are based on the study of the process $e^+ e^- \to W^+ W^-…
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.
Electroweak precision data at LEP are used to place bounds on some $\lambda'$-type ($L$-violating) and $\lambda''$-type ($B$-violating) $R$-parity violating supersymmetric Yukawa couplings. We consider one-loop corrections (triangles and…
Extensions of the Standard Model which involve a new scale, $\Lambda$, may, for energies sufficiently small compared to this new scale, be expressed in terms of operators with energy dimension greater than four. The coefficients of just…
We perform a systematic one-loop renormalization on the electroweak chiral Lagrangian (EWCL) up to $O(p^4)$ operators and construct the renormalization group equations (RGE) for the anomalous couplings. We examine the impact of the triple…
We calculate the electroweak corrections of the order $O({m_t^2\over v^2})$ to the QCD production of $t\bar{t}$ pairs via $q+qbar->t+tbar$ at hadron colliders and show that these corrections to the total production rate are small. This…
An Effective Lagrangian description is useful for describing potential physics beyond the Standard Model. The method is illustrated by reference to interactions among the electroweak bosons ($W^\pm$ \& $Z^0$). The resulting estimates of the…
We evaluate the implications of LHC and LEP/SLC measurements for the electro-weak couplings of the top and bottom quarks. We derive global bounds on the Wilson coefficients of ten two-fermion operators in an effective field theory…
Using an effective Lagrangian approach, we perform a model-independent analysis of the interactions among electroweak gauge bosons and the third generation quarks, i.e. the Wtb, Ztt and Zbb couplings. After one imposes the known…
General non-standard $tbW$ couplings are studied as model independently as possible based on the effective Lagrangian consisting of the dimension-6 operators, which is an extension of the standard-model Lagrangian. The $tbW$-interaction…
It is possible to place direct constraints on WW-photon and WWZ couplings by studying their tree-level contributions to the process e^+e^- ---> W^+W^-. However, these couplings also contribute at the loop level to e^+e^- ---> f fbar…
The standard model for electroweak interactions uses the concepts of weak hypercharge and local gauge invariance of the Lagrangian density under the gauge group SU(2) x U(1). Taylor has remarked that U(1), being a multiply-connected group,…