相关论文: Note on Custodial Symmetry in the Two-Higgs-Double…
In the two-Higgs-doublet model, different Higgs doublets can be viewed as components of a generic "hyperspinor". We decompose the Higgs potential of this model into irreducible representations of the SU(2) group of transformations of this…
We discuss how one can identify CP violation (and conservation) in multi-Higgs-doublet potentials. After a brief review of CP violation in the 2HDM, we refer to the fact that for NHDM with $N \geq 3$ the well known methods useful in the…
We investigate origin of three features that are often assumed in analysis of two-Higgs doublet models: (i) softly broken Z2 symmetry, (ii) CP invariant Higgs potential, and (iii) degenerated mass spectra. We extend electroweak gauge…
The complex 2HDM (C2HDM) is the most general CP-violating two Higgs doublet model that possesses a softly-broken $\mathbb{Z}_2$ symmetry. However, the physical consequences of the model cannot depend on the basis of scalar fields used to…
Conditions for CP violation in the scalar potential sector of general N-Higgs-doublet models (NHDMs) are analyzed from a group theoretical perspective. For the simplest two-Higgs-doublet model (2HDM) potential, a minimum set of conditions…
I discuss methods to identify the presence of dicrete symmetries in the two-Higgs-doublet model by observing the masses and the cubic and quartic interactions of the scalars. The symmetries considered are a $ Z_2 $ symmetry under which $…
Motivated by recent results from the LHC experiments, we analyze Higgs couplings in two Higgs doublet models with an approximate PQ symmetry. Models of this kind can naturally accommodate sizable modifications to Higgs decay patterns while…
A CP-even neutral Higgs boson with Standard-Model-like couplings may be the lightest scalar of a two-Higgs-doublet model. We study the decoupling limit of the most general CP-conserving two-Higgs-doublet model, where the mass of the…
Based on an explicit model, we propose and discuss the generic features of a possible implementation of the Twin Higgs program in the context of composite Higgs models. We find that the Twin Higgs quadratic divergence cancellation argument…
We present new variants of the Two Higgs-Doublet Model where all Yukawa couplings with physical Higgs bosons are controlled by the quark mixing matrices of both chiralities, as well as, in one case, the ratio between the two scalar…
We prove that a generic multi-Higgs-doublet model (NHDM) generally must contain terms in the potential that violate the custodial symmetry. This is done by showing that the O(4) violating terms of the NHDM potential cannot be excluded by…
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 three different classes of CP-symmetries that can be realized in a two-Higgs-doublet model, CP1, CP2 and CP3. We express conditions for realizing these symmetries in terms of masses and couplings of the model, thereby…
We analyze the Large Hadron Collider (LHC) phenomenology of heavy vector resonances with a $SU(2)_L\times SU(2)_R$ spectral global symmetry. This symmetry partially protects the electroweak S-parameter from large contributions of the vector…
Custodial symmetries are common in the Standard Model of particle physics. They arise when quantum corrections to a parameter are proportional to the parameter itself. Here, we show that a custodial symmetry of the chiral type is also…
In this paper, the analytic sufficient and necessary conditions are obtained for the CP conserving two-Higgs-doublet potential to be bounded from below by using the co-positivity of tensors. This is achieved by treating the potential as a…
We present an example of a realistic Higgsless model that makes use of alternative $SU(2)_R$ assignments for the top and bottom quarks recently proposed by Agashe et al. which results in an enhanced custodial symmetry. Using these new…
A vast literature on the theory and phenomenology of Two-Higgs-Doublet models (2HDM) exists since long. However, the present situation demands a revisit of some 2HDM properties. Now that a 125 GeV scalar resonance has been discovered at the…
The generalization of the "custodial symmetry" mechanism which leads to the natural (without fine tuning) explanation of the doublet-triplet hierarchy is suggested in the frames of extended $SU(N\geq 8)$ SUSY GUTs. It is shown also that…
A thorough analysis of stability and perturbativity bounds is performed in several versions of the two-Higgs doublet model, for both CP-conserving and spontaneously broken CP minima. LEP results further aid in establishing very strict…