Constraints on Two Higgs Doublet Models

• Main Authors: Chung, Yi-Lun, 鍾沂倫
• Other Authors: Cheung,Kingman
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/ksqbe8

碩士 === 國立清華大學 === 物理學系 === 105 === We studied the relation between the mass of charged scalar boson and vacuum expectation value ratio(tan β) in the four types 2HDM. According to the constraints on flavor physics B→Xsγ,B0−B0 mixing, Z→bb and Bs→µ+µ−, H± mass in the Type II and Flipped is larger than 500GeV. But there are no constraints on H± mass in the Type I and Lepton Specific when tanβ is larger than 2. On the contrary, in small tanβ region, H± mass becomes larger than 700GeV with the decreasing tanβ. Because mass is so heavy at low tanβ region, we choose that tanβ is larger than 1 in the next step, which is the analysis of the ATLAS Higgs physics data according to the ATLAS paper. Next, we can test new model via signal strength analysis. However, there are information of production and final state both in signal strength. If we want to look into different production µhZZ∗ cross sections, we can define the ratio R≡ VBF/ggh. It is independent to theoretical predictions on partial decay width and branch ratio. Moreover, many experimental systemic uncertainties can be cancelled in this ratio. We choose gg→H→WW∗ for our reference because it has smallest statistical and overall uncertainties. As results of this method, we find that the constraint on the Lepton Specific is better than using ordinary signal strength method.