The properties of Higgs boson in the further LHC search

• Main Authors: Lu, Chih Ting, 盧致廷
• Other Authors: Cheung, Kingman
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/45895196521952467604

博士 === 國立清華大學 === 物理系 === 103 === A new particle with mass of 125~126 GeV was discovered at the Large Hadron Collider (LHC) in July 2012. This may be the long-sought Higgs boson of the standard model (SM), which was proposed in the 1960's, or one of the Higgs beyond the SM. Based on a global analysis of all the Higgs couplings using all the available data at different stages, we propose the following projects to explore the properties of Higgs boson : First, we use the extra U(1) extended MSSM (UMSSM) to explain the enhanced diphoton rate after collecting data at the end of 2012. We also predict the Z photon production rate and study the properties of the other Higgs bosons in the UMSSM. Second, more evidences of this new particle have been collected at the LHC during 2012~2013 suggesting the new boson is likely to be the long-sought Higgs boson in the SM. One pressing question theorists continue to ask is whether this Higgs boson is a lone player responsible for the full electroweak symmetry breaking. Data at that stage still allows room for additional Higgs bosons or some other UV physics that may play a partial role in the electroweak symmetry breaking as well. We use WW scattering to investigate such a possibility, using the two-Higgs-doublet model as a prototype. Finally, the global study of all the Higgs couplings using current data shows that the gauge-Higgs coupling is very close to the SM value, but the Top- and Bottom-Yukawa couplings cannot be determined as precise as gauge-Higgs coupling. We suggest probing the Top-Yukawa coupling in associated Higgs production with a single Top Quark to pin down both the sign and size of the Top-Yukawa coupling.