Related papers: Some remarks on tree-level vacuum stability in two…
We replace the scalar Higgs doublet with a vector Higgs boson doublet to the unified electroweak W-S model and find most of important features of W-S model are kept unchanged only the Higgs boson now become vector bosons. Lorentz invariance…
We discuss the cosmological constant puzzle and possible connections to the (meta-)stability of the Higgs vacuum suggested by recent LHC results. A possible explanation involves new critical phenomena in the ultraviolet, close to the Planck…
We conduct a general discussion of supersymmetric models with three families in the Higgs sector. We analyse the scalar potential, and investigate the minima conditions, deriving the mass matrices for the scalar, pseudoscalar and charged…
Because of the existence of cubic scalar couplings, there are in general nondecoupling effects at tree level in the scalar sector of any theory with two or more very different mass scales. We show this explicitly in the minimal…
The Aligned Two-Higgs-Doublet Model (A2HDM) describes a particular way of enlarging the scalar sector of the Standard Model, with a second Higgs doublet which is aligned to first the one in flavour space. This implies the absence of…
The existence of charged Higgs boson(s) is inevitable in models with two (or more) Higgs doublets. Hence, their discovery would constitute unambiguous evidence for new physics beyond the Standard Model (SM). Taking into account all relevant…
One of the most popular extensions of the Standard Model is the Two-Higgs-Doublet model (2HDM), in which a second Higgs doublet is added to the conventional Standard Model particle content. 2HDM's with a softly broken $\mathbb{Z}_2$…
We analyze the vacuum structure of the one-loop effective potential in the two Higgs doublet model. We find that electroweak-breaking vacuua can coexist with charge breaking ones, contradicting a theorem valid at tree-level. We perform a…
There is a good reason why the standard electroweak SU(2) X U(1) gauge model may be supplemented by two Higgs scalar doublets. They may be remnants of the spontaneous breaking of an SU(2) X SU(2) X U(1) gauge symmetry at a much higher…
We study a three Higgs doublet model where one doublet is inert and the other two doublets are active. Flavor changing neutral currents are avoided at tree-level by imposing a softly broken $Z'_2$ symmetry and we consider type I and type II…
We improve our previously proposed two Higgs doublet model of six-dimensional $SU(4)$ gauge theory compactified on an orbifold $T^2/Z_2$ by introducing the brane localized gauge kinetic terms. Since two Higgs doublets are identified with…
We present the first complete next-to-next-to-leading order analysis of the Standard Model Higgs potential. We computed the two-loop QCD and Yukawa corrections to the relation between the Higgs quartic coupling (lambda) and the Higgs mass…
We point out that the stringent lower bounds on the masses of additional electrically neutral and charged Higgs bosons crucially depend on the flavour structure of their Yukawa interactions. We show that these bounds can easily be evaded by…
After the discovery of a Standard Model-like boson with mass of about 125 GeV the possibility of an enlarged scalar sector arises naturally. Here we present the current status of the phenomenology of the two-Higgs-doublet models with a…
In extensions of the Standard Model with two Higgs doublets, flavour changing Yukawa couplings of the neutral scalars may be present at tree level. In this work we consider the most general scenario in which those flavour changing couplings…
We address the notorious metastability of the standard model (SM) and promote it to a model building task: What are the new ingredients required to stabilize the SM up to the Planck scale without encountering subplanckian Landau poles?…
We perform in the type II seesaw setting, a detailed study of the dynamical features of the corresponding general renormalizable doublet/triplet Higgs potential that depends on five dimensionless couplings and two mass parameters after…
We investigate a new type of a two-Higgs-doublet model as a solution of the muon $g-2$ anomaly. We impose a softly-broken $Z_4$ symmetry to forbid tree level flavor changing neutral currents in a natural way. This $Z_4$ symmetry restricts…
We present a comprehensive analysis of the vacuum stability of the Two-Higgs Doublet Model, for both Type-I and Type-II, augmented by vector-like quarks in either singlet, doublet or triplet representations. We review the model briefly…
We consider two Higgs doublet models (THDMs) with both the Higgs potential and Yukawa interactions being aligned, which we call "double-aligned THDMs". In this scenario, coupling constants of the discovered Higgs boson to the Standard Model…