Study The Higgs Physics And Its Related Topics At LHC

Though the Standard model (SM) has gained great success and Higgs boson with mass around125GeV has been discovered at the Large Hadron Collider (LHC), it is stil-1in progress to investigate the new phenomena induced by many new physics models. Searching for the new physics beyond Standard model is the driving force behind the undergoing experiments at the LHC, which has the potential to discover the new parti-cles which appear in some new physics models after the center of mass energy has been updated to8TeV. As one of the simplest possible extensions of SM, Two-Higgs-Doublet model (2HDM), the feature of which is the existence of the charged Higgs boson H±, whose discovery will be an unambiguous evidence for an extended Higgs sector. The SM is briefly introduced as well as the new particles H±and W’ from the new theory beyond the SM, and we focus the study on the H±, W’ physics and the related topics at LHC. The Type-II2HDM is the most studied by far in various2HDMs. In Type-II2HDM as the theoretical framework, we investigate the possibility to discover the charged Higgs via pp→W±H±→l+ET+bbjj process at LHC, which suffers from large QCD backgrounds. We optimize the kinematic cuts to suppress the backgrounds, so that the reconstruction of the charged Higgs through hadronic decay is possible. The angular distribution of the b-jet from H±decay is investigated as a way to identify the charged scalar from vector bosons. As the following work, the charged Higgs produc-tion is studied at LHC via its associated production with top quark. The kinematic cuts are applied to reconstruct the charged Higgs and top quark, and we proposed the angu-lar distributions with respect to top quark spin is helpful to study the Htb interaction at LHC. A variety of new physics models predict the existence of extra charged gauge bosons (W’) with the same charge as H±which can decay to bt (tb). For the integrity of the research, We study the collider signatures of multi-jets+lepton+ET by recon-structing the tW’ intermediate state through the decay modes of W’→tb, W’→qq’ and W’→lv respectively. An angular distribution related to final state particle and top quark moving direction is provided to distinguish alternative left-handed or right-handed chiral couplings of W’ to quarks in the hadronic decay modes. We adopt various kinematic cuts to depress the backgrounds and collect the integral luminosity needed for the corresponding process detected at the LHC with3α sensitivity. A forward-backward asymmetry which is related to the chirality of W’ is also provided.