A general proof of the equivalence theorem in electroweak theories with the symmetry breaking sector described by the chiral Lagrangian is given in the Rξ gauge by means of the Ward-Takahashi identities. The precise form of the theorem contains a modification factor Cmod associated with each external Goldstone boson similar to that in the standard model. Cmod is exactly unity in our previously ...

Electroweak interactions need three Nambu–Goldstone bosons to provide a mass to the W ± and the Z gauge bosons but they also need an ultraviolet (UV) moderator or new physics to unitarize the gauge boson scattering amplitudes. In this talk, I will present various recent models of physics at the Fermi scale: several deformations of the Minimal Supersymmetric Standard Model, Little Higgs models, ...

In a class of models of dynamical symmetry breaking not ruled out by the available data, the lightest neutral pseudo-Nambu-Goldstone boson (P ) contains only down-type techniquarks and charged technileptons. Its mass scale is naturally determined by the b-quark and therefore it is likely to be light. As the presence of pseudo-Nambu-Goldstone bosons in models of dynamical symmetry breaking is a ...

We study new physics effects to the quartic gauge boson couplings formulated by the electroweak chiral Lagrangian. Five next-to-leading order operators characterize the anomalous quartic gauge interactions which involve pure Goldstone boson dynamics for the electroweak symmetry breaking. We estimate the typical size of these couplings in different strongly-interacting models and examine the sen...

In this, the first of three papers, we present the essential features of a treatment of the U( 1) -Higgs model based upon a regulator free, momentum space subtraction scheme. The principle new results which follow from this approach are: (1) the fields of the theory satisfy their classical equations of motion, (2) the source of the vector meson field, f(x), is a finite, conserved current, (3) t...

The supersymmetric extension of the economical 3-3-1 model is presented. The constraint equations and the gauge boson identification establish a relation between the vacuum expectation values (VEVs) at the top and bottom elements of the Higgs triplet χ and its supersymmetric counterpart χ′. Because of this relation, the exact diagonalization of neutral gauge boson sector has been performed. The...

Using an exact solution as a concrete example, Nambu-Goldstone modes on the BPS domain wall junction are worked out for N = 1 supersymmetric theories in four dimensions. Their wave functions extend along the wall to infinity (not localized) and are not normalizable. It is argued that this feature is a generic phenomenon of Nambu-Goldstone modes on domain wall junctions in the bulk flat space in...

We analyze a composite Higgs model based on the confining $SU(3)$ gauge theory with ${N}_{f}=8$ Dirac fermions in fundamental representation. This has been studied lattice and shown to be well described by dilaton effective field (EFT). Here we modify EFT assigning standard-model quantum numbers such that four of pseudo-Nambu-Goldstone boson (pNGB) fields form doublet, coupling it top quark add...