Related papers: Collective Quartics and Dangerous Singlets in Litt…
While little Higgs models provide an interesting way to address the hierarchy problem, concrete models in the literature typically face two major obstacles. First, the mechanism for generating a Higgs quartic coupling often leads to large…
We discuss the realization of two Higgs doublets model in the framework of 6 dimensional Gauge-Higgs Unification model with a simple Lie group G_M. Two Higgs SU(2)_L doublets can emerge at the low energy effective theory, and the quartic…
In Little Higgs models a collective symmetry prevents the higgs from acquiring a quadratically divergent mass at one loop. We have previously shown that the couplings in the Littlest Higgs model introduced to give the top quark a mass do…
This article classifies Little Higgs models that have collective quartic couplings. There are two classes of collective quartics: Special Cosets and Special Quartics. After taking into account dangerous singlets, the smallest Special Coset…
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…
The fundamental Higgs doublet may be replaced in the Standard Model by certain non-perturbative four-quark interactions, whose effect is to induce a composite Higgs sector responsible for electroweak symmetry breaking. A simple composite…
We show how a heavy scalar singlet with a large vacuum expectation value can evade the potential instability of the Standard Model electroweak vacuum. The quartic interaction between the heavy scalar singlet and the Higgs doublet leads to a…
We present an economical theory of natural electroweak symmetry breaking, generalizing an approach based on deconstruction. This theory is the smallest extension of the Standard Model to date that stabilizes the electroweak scale with a…
In little higgs models a collective symmetry prevents the higgs from acquiring a quadratically divergent mass at one loop. By considering first the littlest higgs model we show that this requires a fine tuning: the couplings in the model…
This article reviews the Little Higgs models of electroweak symmetry breaking and their phenomenology. Little Higgs models incorporate a light composite Higgs boson and remain perturbative until a scale of order 10 TeV, as required by…
We investigate the general two Higgs doublet model imposing both the unitarity conditions and the bounded-from-below conditions. Both types of conditions restrict the ranges of the parameters of the scalar potential. We study the model in…
We study a simple extension of the standard model where scalar singlets that mix with the Higgs doublet are added. This modification to the standard model could have a significant impact on Higgs searches at the LHC. The Higgs doublet is…
Little Higgs theories are an attempt to address the little hierarchy problem, i.e., the tension between the naturalness of the electroweak scale and the precision measurements showing no evidence for new physics up to 5-10 TeV. In little…
Recently a new class of theories of electroweak symmetry breaking have been constructed. These models, based on deconstruction and the physics of theory space, provide the first alternative to weak-scale supersymmetry with naturally light…
If the LHC does only find a Higgs boson in the low mass region and no other new physics, then one should reconsider scenarios where the Standard Model with three right-handed neutrinos is valid up to Planck scale. We assume in this spirit…
Scenarios in which the Higgs vacuum arises radiatively and is separated from the origin by a potential barrier at zero temperature are known to be attainable in models with extra singlet scalars, which in the limit of zero barrier height…
We consider a minimal extension of the standard model where a real, gauge singlet scalar field is added to the standard spectrum. Introducing the Ansatz of universality of scalar couplings, we are led to a scenario which has a set of very…
Light, electrically charged vector-like `leptons' with order one Yukawa couplings can enhance the Higgs to diphoton decay rate, as is suggested by measurements of the signal strength \mu_{\gamma\gamma} by ATLAS and CMS. However, the large…
In the Standard Model (SM), the Higgs mass around 125 GeV implies that the electroweak vacuum is metastable since the quartic Higgs coupling turns negative at high energies. I point out that a tiny mixing of the Higgs with a heavy singlet…
In this paper we have considered the possibility that the Standard Model, and its minimal extension with the addition of singlets, merges with a high-scale supersymmetric theory at a scale satisfying the Veltman condition and therefore with…