Related papers: Light Sparticles from a Light Singlet in Gauge Med…
Searches for the Standard Model Higgs boson by the four LEP experiments found excess events in two mass ranges: a 2.3 sigma excess around 98 GeV, and an 1.7 sigma excess around 115 GeV. The latter has been discussed widely in the…
In the context of minimal supersymmetric standard model (MSSM), we discuss the possibility of the lightest Higgs boson with mass $M_h = 98 $ GeV to be consistent with the $2.3\sigma$ excess observed at the LEP in the decay mode $e^+e^- \to…
With the Higgs search program already quite mature, there is the exciting possibility of discovering a new particle with rates near that of the SM Higgs. We consider models with a signal in $\gamma \gamma$ below the SM Higgs mass, taking…
To obtain a SM-like Higgs boson around 125 GeV in the Minimal Supersymmetric Standard Model with minimal gauge mediation of supersymmetry breaking (GMSB), a heavy stop at multi-TeV level is needed and incurs severe fine-tuning, which can be…
We show that in the Minimal Supersymmetric Standard Model, the possibility for the lightest CP-even Higgs boson to be lighter than $Z$ boson (as low as about 60 GeV) is, contrary to the usual belief, not yet excluded by LEP2 data or any…
The naturalness of a Higgs boson with a mass near 125 GeV is explored in a variety of weak-scale supersymmetric models. A Higgs mass of this size strongly points towards a non-minimal implementation of supersymmetry. The Minimal…
We consider minimal models of gauge mediated supersymmetry breaking with an extra $U(1)$ factor in addition to the Standard Model gauge group. A $U(1)$ charged, Standard Model singlet is assumed to be present which allows for an additional…
We propose that the TeV scale mirage mediation in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) is a novel solution for the little hierarchy problem in supersymmetry. The 125 GeV Higgs boson can be accommodated with the new…
We reexamine the models with gauge mediation in view of the minimality. As a result, we arrive at a very simple model of direct gauge mediation which does not suffer from the flavor problems nor the CP problems. We show that the parameter…
Most models of new physics contain extended Higgs sectors with multiple Higgs bosons. The observation of an additional Higgs boson, besides the $\sim 125$ GeV `$h_{\rm obs}$', will thus serve as an irrefutable evidence of physics beyond the…
A search for a very light Higgs boson decaying into a pair of tau leptons is presented within the framework of the next-to-minimal supersymmetric standard model. This search is based on a data set corresponding to an integrated luminosity…
In a recent paper we showed that the Minimal R-symmetric Supersymmetric Standard Model (MRSSM) can accommodate the observed 125 GeV Higgs boson as the lightest scalar of the model in agreement with electroweak precision observables, in…
The minimal supersymmetric standard model, and extensions, have stringent upper bounds on the mass of the lightest Higgs boson if perturbativity up to the Planck scale is assumed. We argue that these bounds are softened tremendously if the…
A preliminary combined mass limit of about 90 GeV has been reported for the Minimal Standard Model Higgs boson from the 183 GeV data taken in 1997, with a total luminosity of about 200 pb-1. Similar mass limits have been reported from the…
In the Minimal Supersymmetric Standard Model, the higgsinos can have masses around the electroweak scale, while the other supersymmetric particles have TeV-scale masses. This happens in models of gauge-mediated SUSY breaking with a high…
In order to reproduce the measured mass of the Higgs boson mh = 125GeV in the minimal supersymmetric standard model, one usually has to rely on heavy stops, increasing the fine tuning of the electroweak scale. By introducing a new gauge…
We show that the gauge mediation models with vector-like matters can explain the Higgs boson mass of 126 GeV without large soft scalar masses nor a large left-right mixing of the stops. The scenario has interesting features: the existence…
We review recent progress in techniques for searching for the Standard Model light `Intermediate Mass' Higgs Boson ($80 \GeV \lsim M_H \lsim 140\GeV$). We pay particular attention to associated production at the SSC and LHC where we search…
We have found that in the MSSM, the possibility for the lightest CP-even Higgs boson to be lighter than $Z$ boson (as low as about 60 GeV) is, contrary to the usual belief, not yet excluded by LEP2 Higgs search nor any direct searches for…
The Next to Minimal Supersymmetric Standard Model (NMSSM) with a Higgs-singlet coupling {\lambda} close to unity, moderate tan {\beta} and stop masses below 1 TeV minimizes the fine tuning of the electroweak scale, making possible that the…