The production process of the charged Higgs-boson associated with a W boson at electron-positron colliders is discussed in the two-Higgs-Doublet Model (2HDM) and in the Minimal Supersymmetric Standard Model (MSSM). The process is induced at one-loop level in these models. We examine how much the cross section can be enhanced by quarkand Higgs-loop effects. In the non-SUSY 2HDM, in addition to l...

The dominance of h → ηη decay mode for the intermediate mass Higgs boson is highly motivated to solve the little hierarchy problem and to ease the tension with the precision data. However, the discovery modes for mh ∼ 150 GeV, h → γγ and W/Zh → (lν/ll̄)(bb̄), will be substantially affected. We show that h → ηη → 4b is complementary and we can use this decay mode to detect the intermediate Higgs b...

The prospects for Higgs boson discovery and study at present and future colliders are reviewed, with emphasis on the Minimal Supersymmetric Standard Model (MSSM) states. The expected experimental coverages with different production and decay modes are outlined. Particular attention is given to the Higgs couplings predicted when the top quark Yukawa coupling has an infrared fixed point. Characte...

[Abstract] In this paper, applying general gauge field theory, we will construct an electroweak model. In this new electroweak model, Higgs mechanism is not used, so no Higgs particle exists in the model. In order to keep the masses of intermediate gauge bosons non-zero, we will introduce two sets of gauge fields. We need a vacuum potential to introduce symmetry breaking and to introduce the ma...

We calculate the change in the ultraviolet behaviour of the vortex operator due to the presence of dynamical Higgs field in both 2+1 dimensional QED and the 2+1 dimensional Georgi-Glashow model. We find that in the QED case the presence of the Higgs field leads at the one loop level to power like correction to the propagator of the vortex operator. On the other hand, in the Georgi-Glashow model...

We point out that charged Higgs bosons can decay into final states different from τντ and cs̄, even when they are light enough to be produced at LEP II or at the Tevatron through top quark decays. These additional decay modes are overlooked in ongoing searches even though they alter the existing lower bounds on the mass of the charged Higgs bosons that are present in supersymmetric and two Higgs...

We investigate a possibility if a loop diagram via Higgsino can enhance the Higgs to diphoton decay width in supersymmetric models with an extension of Higgs sector. A model with an additional non-renormalizable term of Higgs fields is firstly analyzed where the higher order term can introduce the Higgs coupling to Higgsinos as well as charged Higgs bosons. We point out that a choice of the Hig...

We obtain tree-level unitarity constraints for the Two Higgs Doublet Model (2HDM) with explicit CP -violation. We limit ourselves to the case with soft violation of the discrete Z2 symmetry of theory. The key role is played by the rephasing invariance of the 2HDM lagrangian. Our simple approach for derivation of these constraints can be easily transferred to other forms of Higgs sector. We brie...

The two-Higgs-doublet model provides a simple, yet interesting, generalization of the SM Higgs sector. We study the CP-conserving version of this model with general, flavor-diagonal, Yukawa couplings. Indirect constraints are obtained from flavor physics on the charged Higgs boson mass and couplings. The relation of these bounds to those for the more specialized two-Higgsdoublet model types wit...

The phase structure of lattice Higgs model has been studied by many authorsl)-4) with radial excitations of the Higgs scalar frozen out. Revealed was a remarkable feature of complementarityl),5) which states that, in Higgs models with a scalar in the fundamental representation, the Higgs and the confining phases are analytically connected with each other. Many applications of the complementarit...