The Study Of Light Higgs Scalar In The NMSSM

Nowadays the phenomenological study of Higgs physics is one of the most important topics in high energy physics. With the operating of the Large Hadron Collider in European physicists will continuous open the mysterious veil of the Higgs physics. In July2012, both the ATLAS and the CMS collaborations have observed a new state with a mass of about125GeV, whose properties are in substantial agreement with the SM Higgs boson. However, the quest for understanding the mechanism behind the electroweak symmetry breaking does not end with the discovery of the Higgs boson. It is an important advance and implies that the mechanism of Higgs is right. Obviously, there exists new physic out of stand model.Therefore it is crucial to test the Higgs boson potential to its full extent, measuring the couplings of the Higgs boson to gauge bosons and matter fields, and also probing its self-interactions. Measurements of the properties of Higgs boson have been a key indicator for distinguishing different scenarios and also could be used to search for the agent of electroweak symmetry breaking. Confronted with these questions, in this thesis, we perform a phenomenological study on the Higgs boson in the next-to-minimal supersymmetric standard model (NMSSM).In the Next-to-Minimal Supersymmetric Standard Model (NMSSM), one of the neutral Higgs scalars (CP-even or CP-odd) may be lighter than half of the SM-like Higgs boson, In this case, the SM-like Higgs boson h can decay into such a light scalar pair and consequently the yy and ZZ*signal rates at the LHC will be suppressed. In this work, we examine the constraints of the latest LHC Higgs data on such a possibility.Firstly, we perform a comprehensive scan over the parameter space of the NMSSM by considering various experimental constraints and find that the LHC Higgs data can readily constrain the parameter space and the properties of the light scalar, e.g., at3σ level this light scalar should be highly singlet dominant and the branching ratio of the SM-like Higgs boson decay into the scalar pair should be less than30%.What’s more, we investigate the detection of this scalar at various colliders. Through a detailed Monte Carlo simulation we find that under the constraints of the current Higgs data this light scalar can be accessible at the LHC-14with an integrated luminosity over300fb-1.With the accumulate of Higgs Data and the experimental advancement of High Energy Physics detect technology, our discussion is necessary in seeking for the light scalar via the future collider.