相关论文: Status of negative coupling modifiers for extended…
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…
We explore the radiative corrections to the process $Z \to b \bar b$ in models with extended Higgs sectors. The observables $R_b = \Gamma(Z \to b \bar b)/\Gamma(Z \to \rm{hadrons})$ and the $Z b \bar b$ coupling asymmetry, $A_b = (g_L^2 -…
We calculate 1-loop radiative corrections to the $hZZ$ and $hWW$ couplings in models with next--to--simplest Higgs sectors satisfying the electroweak $\rho$ parameter equal to 1 at tree level: the Higgs singlet model, the two-Higgs doublet…
Type-Z models, where charged leptons, up type quarks, and down type quarks each couple to a different scalar, are only possible when there are three or more Higgs doublets. We consider the Type-Z three Higgs doublet model imposed by a…
It has been recently argued that realistic models with warped extra dimensions can have Kaluza-Klein particles accessible at the Large Hadron Collider if a custodial symmetry, SU(2)_V \times P_{LR}, is used to protect the T parameter and…
In non-minimal Higgs sectors, coupling constants of the discovered Higgs boson can deviate from the predictions in the Standard Model by effects of additional scalar bosons. The pattern of the deviations in various Higgs boson couplings…
Electroweak precision measurements established that custodial symmetry is preserved to a good accuracy in the gauge sector after electroweak symmetry breaking. However, recent LHC results might be interpreted as pointing towards Higgs…
We discuss the phenomenology of several Beyond the Standard Model (SM) extensions that include extended Higgs sectors. The models discussed are: the SM extended by a complex singlet field (CxSM), the 2-Higgs-Doublet Model with a…
The $SU(2){-}$gauged custodial two-Higgs-doublet model, which shares the same global-symmetry properties with the standard model, is studied non-perturbatively on the lattice. The additional Higgs doublet enlarges the scalar spectrum and…
In the standard model (SM), the $\rho$ parameter is equal to 1 and the ratio $\lambda_{WZ}$ of Higgs $\to ZZ$ and Higgs $\to WW$ is also equal to 1 at the tree level. When going beyond the SM with more than one types of Higgs…
Beyond the Standard Model (SM) extensions usually include extended Higgs sectors. Models with singlet or doublet fields are the simplest ones that are compatible with the $\rho$ parameter constraint. The discovery of new non-SM Higgs bosons…
We study the conditions of maximal $CP$ violation in the neutral Higgs mass matrix of the two Higgs doublet model. We get fixed values of $\tan\b$ and constraints on the Higgs potential parameters. Two neutral Higgs scalars are constrained…
We examine the use of modified Higgs sectors to address the little hierarchy problem of supersymmetry. Such models reduce weak-scale fine-tuning by allowing lighter stops, but they retain some fine-tuning independent of the Higgs. The…
The neutral Higgs sector of the next-to-minimal supersymmetric standard model (NMSSM) with explicit CP violation is investigated at the 1-loop level, using the effective potential method; not only the loops involving the third generation of…
We investigate possible symmetry properties of the scalar sector of Multi-Higgs-Doublet Models, and, to some extent, the generalization of such models to gauge groups other than $SU(2)_L\times U(1)_Y$. In models where the ${\cal C}$ (charge…
We present a comprehensive study of the modifications of Higgs couplings in the SO(5)/SO(4) minimal composite model. We focus on three couplings of central importance to Higgs phenomenology at the LHC: the couplings to top and bottom quarks…
We analyse the neutral scalar sector of the MSSM without R-parity. Our analysis is performed for a one-generation model in terms of ``basis-independent'' parameters, and includes one-loop corrections due to large yukawa couplings. We…
We perform a detailed study of the exclusive Higgs decays $h\to MZ$ and $h\to MW$, where $M$ is a pseudoscalar or vector meson, using the QCD factorization approach. We allow for the presence of new-physics effects in the form of modified…
We study the scattering of longitudinally polarized W bosons in extensions of the Standard Model where anomalous Higgs couplings to gauge sector and higher order O(p^4) operators are considered. These new couplings with respect to the…
The Higgs trilinear coupling $\lambda_{hhh}$ is of great importance to understand the structure of the Higgs sector and allows searching for indirect signs of Beyond-the-Standard-Model (BSM) physics, even if new states are somehow hidden.…