Related papers: On Non-Standard Couplings among the Electroweak Ve…
This study explores the parameter space of a minimal extension of the Standard Model with a non-abelian $SU(2)$ group, in which the gauge bosons are stable and acquire mass through a mechanism of spontaneous symmetry breaking involving a…
The review of the measurements of the gauge couplings in the boson sector at LEP is presented. The measurements of the charged triple gauge couplings (cTGC) parameters from the four LEP experiments are combined and the results are in good…
There are theoretical speculations that the top quark may have different properties from that predicted by the standard model. We use an effective Lagrangian technique to model such a non-standard top quark scenario and study its effects on…
Non-decoupling effects of heavy particles present in beyond-the-standard models are studied for the triple gauge boson vertices $\gamma W^+W^-$ and $Z^0W^+W^-$. We show from a general argument that the non-decoupling effects are described…
The gauge parameter dependence of QED in the covariant gauge can be determined explicitly by introducing a Stueckelberg field, which is a non-interacting fictitious Goldstone boson field. Examples of QED with electrons or charged scalars…
We recently studied possible non-standard tbW couplings based on the effective-Lagrangian which consists of four kinds of SU(3) x SU(2) x U(1) invariant dimension-6 effective operators and gave an experimentally allowed region for each…
Recent analyses suggest that in TeV scales that will be made accessible at the LHC copious amounts of color scalar parton bound states may be produced. Would this be the case, the scalars would leave long enough to interact and this could…
Gauge invariance is a powerful tool to determine the dynamics of the electroweak and strong forces. The particle content, structure and symmetries of the Standard Model Lagrangian are discussed. Special emphasis is given to the many…
Gauge invariance is a powerful tool to determine the dynamics of the electroweak and strong forces. The particle content, structure and symmetries of the Standard Model Lagrangian are discussed. Special emphasis is given to the many…
We present a model and process independent study of the contributions from non-Standard Model physics to the oblique parameters S, T and U. We show that within an effective lagrangian parameterization the expressions for the oblique…
We define a family of non local and chirally symmetric low energy lagrangians motivated by theoretical studies on Quantum Chromodynamics. These models lead to quark propagators with non trivial momentum dependencies. We define the formalism…
This is a study of induced nonlinear realizations of a Lie group G in which the presence of one field induces nonlinear transformations on another field. The covariant derivative structure is similar in form to that for local gauge theory.…
We use the external field method to study the electroweak chiral Lagrangian of the extra dimension model with brane fluctuation. Under the assumption that the contact terms between the matters of the standard model and KK excitations are…
Gauge invariance is a powerful tool to determine the dynamical forces among the fundamental constituents of matter. The particle content, structure and symmetries of the Standard Model Lagrangian are discussed. Special emphasis is given to…
We briefly discuss the first direct experimental evidence from LEP2 on non-vanishing trilinear couplings among the weak vector bosons. Subsequently we review the improved Born approximation to include radiative corrections. Provided the…
We study the reduction of non-autonomous regular Lagrangian systems by symmetries, which are generated by vector fields associated with connections in the configuration bundle of the system $Q\times\real\to\real$. These kind of symmetries…
For an autonomous system the symmetries of the Lagrangian are embedded in the symmetries of the differential equation. Recently, it has been found that the modified Emden-type equations follow from non-standard Lagrangian functions which…
We reconsider the gauge symmetries of the spinning particle by a direct examination of the Lagrangian using a systematic procedure based on the Noether identities. It proves possible to find a set of local Bosonic and Fermionic gauge…
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…
These four lectures constitute a gentle introduction to what may lie beyond the standard model of quarks and leptons interacting through $SU(3)_c \otimes SU(2)_L \otimes U(1)_Y$ gauge bosons, prepared for an audience of graduate students in…