Related papers: Physical parameters and basis transformations in t…
We present a consistent renormalization scheme for the CP-conserving Two-Higgs-Doublet Model based on $\overline{MS}$ renormalization of the mixing angles and the soft-$Z_2$-symmetry-breaking scale $M_{sb}$ in the Higgs sector. This scheme…
Recently, the CDF collaboration has reported a new precision measurement of the $W$-boson mass, $M_W$, showing a large deviation from the value predicted by the Standard Model (SM). In this paper, we analyse possible new physics…
The basic physics disciplines of Maxwell's electrodynamics and Newton's mechanics have been thoroughly tested in the laboratory, but they can nevertheless also support nonphysical solutions. The unphysical nature of some dynamical…
In a model with more than one scalar doublet, the parameter space encloses both physical and unphysical information. Invariant theory provides a detailed description of the counting and characterization of the physical parameter space. The…
In this letter we study the specific sensitivity and constraints to the soft breaking $Z_2$ parameter $m_{12}$ of the Two Higgs Doublet Model (2HDM). $m_{12}$ is considered here as an input parameter of the model together with the masses of…
We consider the general Three-Higgs Doublet Model (3HDM) and identify all limits that lead to exact SM alignment. After discussing the underlying symmetries that can naturally enforce such an alignment, we focus on the most economic…
The existence of supersymmetry above a few TeV and that of two Higgs doublets at the electroweak energy scale do not necessarily result in the minimal supersymmetric standard model (MSSM). An interesting counter example is given with m_h <…
Constraints on the two Higgs doublet model are presented, assuming a top mass of 174 $\pm$ 17 GeV. We concentrate primarily on the ``type II'' model, where up--type quarks receive their mass from one Higgs doublet, and down--type quarks…
Present data, both from direct Higgs search and from analysis of electroweak data, are starting to become rather restrictive on the possible values for the mass of the standard model Higgs. We discuss a new physics scenario based on a model…
Higgs sector extensions beyond the Standard Model (BSM) provide additional sources of CP violation and further scalar states that help to trigger a strong first order electroweak phase transition (SFOEWPT) required to generate the observed…
We show that if the Standard Model gauge fields and fermions propagate in extra dimenions, a composite Higgs field with the correct quantum number can arise naturally as a bound state due to the strong gauge interactions in higher…
We study the possibility of radiative electroweak symmetry breaking where loop corrections to the mass parameter of the Higgs boson trigger the symmetry breaking in various extensions of the Standard Model (SM). Although the mechanism fails…
We investigate high scale boundary conditions on the quartic Higgs-couplings and their $\beta$-functions in the Type-II Two Higgs Doublet Model and the Inert Doublet Model. These conditions are associated with two possible UV physics…
The Two Higgs Doublet Model invariant under the gauge group SU(2)xU(1) is known to have six additional global discrete or continuous symmetries of its scalar sector. We have discovered regions of parameter space of the model which are basis…
Assuming the existence of a supersymmetric U(1) gauge factor at the TeV energy scale (motivated either by the superstring-inspired E_6 model or low-energy electroweak phenomenology), several important consequences are presented. The…
We investigate the strength of the electroweak phase transition (EWPT) within the CP-violating 2-Higgs-Doublet Model (C2HDM). By applying a renormalisation scheme which allows efficient scans of the C2HDM parameter space, we analyse the…
We obtain the mass spectrum and the Higgs self-coupling of the two Higgs doublet model (THDM) in an alternative unification scenario where the parameters of the Higgs potential $\lambda_i$ ($i=1,2,3,4,5$) are determined by imposing their…
We discuss the prediction of the $W$ boson mass in a simple extension of the Standard Model ($\Sigma {\rm SM}$) with a real scalar triplet. A shift in the $W$ mass as reported by the CDF II collaboration can naturally be accommodated by the…
We study the phenomenology of gauge singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. We determine the conditions on the scalar potential parameters that lead to a strong…
We study the indirect effects of new physics on the phenomenology of the recently discovered "Higgs-like" particle. In a model independent framework these effects can be parametrized in terms of an effective Lagrangian at the electroweak…