The Standard Model (SM) requires a Higgs boson to explain the generation of fermion and gauge boson masses. The precise electroweak (EW) measurements at LEP suggest that the Higgs boson must be relatively light1, with mH < 219 GeV. A light Higgs is also required in order to unitarize the longitudinal WL −WL scattering amplitude2. In addition, the triviality bound indicates that the SM with a li...

Higgs Mixing in the NMSSM and Light Higgsinos Kwang Sik Jeong a,b∗, Yutaro Shoji c†, Masahiro Yamaguchi c‡ a DESY, Notkestrasse 85, 22607 Hamburg, Germany b Center for Theoretical Physics of the Universe, IBS, Daejeon 305-811, Korea c Department of Physics, Tohoku University, Sendai 980-8578, Japan Abstract We explore the effects of Higgs mixing in the general next-to-minimal supersymmetric Sta...

Several topics related to phenomenology of the Higgs sector in the supersymmetric standard model are reviewed. The upper bound of the lightest Higgs mass in the minimal supersymmetric standard model as well as extended version of it is discussed and it is shown that an ee linear collider with √ s ∼ 300−500 GeV can find at least one Higgs boson in these models. It is also pointed out that the he...

Large Hadron Collider (LHC) experiments this year have shown the existence of a new boson that resembles the Higgs boson. Although it is known that this particle has couplings to other particles that increase with their masses, the spin of the newly discovered boson is undetermined as of yet. The Higgs boson has been predicted to be a spin 0 particle. The LHC boson is not a spin 1 particle, sug...

We present explicit analytic results for the two-loop top/stop/gluino contributions to the cross section for Higgs boson production via gluon fusion in the MSSM, under the approximation of neglecting the Higgs boson mass with respect to the masses of the particles circulating in the loops. The results are obtained employing the low-energy theorem for Higgs interactions adapted to the case of pa...

We investigate the neutral Higgs sector of the minimal supersymmetric standard model in explicit CP violation scenario. Within the context of the effective potential formalism, the masses of the neutral Higgs bosons at the one-loop level are calculated by taking into account the contributions of the following loops of ordinary particles and superpartners: top quark, the scalar top quarks, botto...

A search for the standard model Higgs boson at LEP is reported. In the following, the results obtained by combining all standard model Higgs boson search channels of the experiments (at the end of run in the year 2000) are discussed. The data favour slightly a signal-andbackground hypothesis. The excess over the background would be consistent with the existence of a standard model Higgs boson a...

We analyze the prospects of the Tevatron for finding a Higgs boson in the two photon decay mode. We conclude that the Standard Model (SM) Higgs boson will likely not be discovered in this mode. However, we motivate several theories beyond the SM, including the MSSM, that predict a Higgs boson with enhanced branching fractions into photons, and calculate the luminosity needed to discover a gener...

The differences between the on-shell mass and width of the Higgs boson and their pole counterparts are evaluated in leading order. For a heavy Higgs boson, they are found to be sensitive functions of the gauge parameter and become numerically large over a class of gauges that includes the unitary gauge. For a light Higgs boson, the differences remain small in all gauges. The pinch-technique mas...

We calculate four-fermion decays of a Higgs boson via WW and/or ZZ intermediate states for Higgs masses below mW . We examine models with a doublycharged Higgs boson H and show that the four-fermion decay is the dominant mode for a wide range of parameter space. Existing searches for H in Z decays have not looked for this mode. We also derive four-fermion decay rate for a neutral Higgs boson.