Related papers: The minimal linear sigma model for the Goldstone H…
The spontaneous breaking of linearly realized N=1 supersymmetry implies the existence of a pseudo-Goldstone fermion, the goldstino, and of its complex scalar superpartner, the sgoldstino. The latter has generically sizable tree-level…
We propose the minimal, lepton-number conserving, SU(3)xSU(2)xU(1) gauge-singlet, or phantom, extension of the Standard Model. The extension is natural in the sense that all couplings are of O(1) or forbidden due to a phantom sector global…
We discuss the Higgs sector of the supersymmetric standard model extended by a gauge singlet for the range of parameters, which is compatible with universal soft supersymmetry breaking terms at the GUT scale. We present results for the…
Little Higgs models offer a new way to address the hierarchy problem, and give rise to a weakly-coupled Higgs sector. These theories predict the existence of new states which are necessary to cancel the quadratic divergences of the Standard…
We propose a four dimensional description of Composite Higgs Models which represents a complete framework for the physics of the Higgs as a pseudo-Nambu-Goldstone boson. Our setup captures all the relevant features of 5D models and more in…
Using an effective Lagrangian approach we analyze a generic Higgsless model with composite heavy fermions, transforming as SU(2)_{L+R} Doublets. Assuming that the Standard Model fermions acquire mass through mixing with the new heavy…
The recent results from the ATLAS and CMS collaborations show that the allowed range for a Standard Model Higgs boson is now restricted to a very thin region. Although those limits are presented exclusively in the framework of the SM, the…
We consider a supersymmetric realization of the MSSM Higgs sector, where the soft terms are promoted to supersymmetric operators and a minimal weakly coupled hidden sector is included. The model exhibits long-lived meta-stable vacua in…
By invoking the existence of a general custodial O(2) symmetry, a minimal Left-Right symmetric model based on the gauge group G=SU(2)L SU(2)R U(1)BL is shown to require the existence of only two physical Higgs bosons. The lighter Higgs is…
We use a functional approach based on the background-field formalism and the expansion by regions to integrate out the heavy Higgs field (associated with the mass eigenstate H) in a singlet extension of the Standard Model (SM) at the…
The Minimal Supersymmetric extension of the Standard Model provides a solution to the hierarchy problem and leads to the presence of a light Higgs. A Higgs boson with mass above the present experimental bound may only be obtained for…
We study the implications for the minimal supersymmetric standard model (MSSM) of the absence of a direct discovery of a Higgs boson at LEP. First we exhibit 15 physically different ways in which one or more Higgs bosons lighter than the…
In this work we find the minimal extension of the Standard Model's Higgs sector which can lead to a light Higgs boson via radiative symmetry breaking and is consistent with the phenomenological requirements for a low-energy realization of a…
The $U_L(2)\bigotimes U_R(2) $ gauge model for the unified theory of the electromagnetic and weak interactions which is free from a prior self-interaction scalar field, is developed. Due to breaking the initial symmetry the…
We consider models with multiple Higgs scalar gauge singlets and the resulting restrictions on the parameters from precision electroweak measurements. In these models, the scalar singlets mix with the SU(2) Higgs doublet, potentially…
In the standard model (SM) the condition that the Higgs mass parameter vanishes is stable under radiative corrections and yields a theory that can be renormalized using dimensional regularization. Thus, this model allows to predict the…
A Higgsless model for strong, electro-weak and gravitational interactions is proposed. This model is based on the local symmetry group SU(3)xSU(2)xU(1)xC where C is the local conformal symmetry group. The natural minimal conformally…
We study the minimal set of Higgs scalars, for models based on the local gauge group $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$ which do not contain particles with exotic electric charges. We show that only two Higgs $SU(3)_L$ triplets are…
We analyze models of electroweak symmetry breaking in warped 5-dimensional space with gauge bosons and fermions in the bulk. The Higgs boson is identified with the 5th component of a gauge field. We dynamically generate the Higgs potential…
Composite Higgs models provide an attractive solution to the hierarchy problem. However, many realistic models suffer from tuning problems in the Higgs potential. There are often large contributions from the UV dynamics of the composite…