Electroweak Symmetry Breaking New Physics And LHC Phenomenon Research

The Standard Model（SM）, which was established in the late1960s, has been demon-strated as an extremely accurate description of the elementary particle physics by tremen-dous amount of experiments conducted over the last40years. It has unified almost allelementary particles and their interactions, including matter particles（three generationsquarks and leptons）, gauge bosons which mediating electromagnetic, weak, strong in-teractions, and scalar boson Higgs which give fermions and gauge bosons their masses.However, the SM still has some fundamental problems（e.g.undescribed gravity, fine tun-ing, triviality, vacuum stability, and too many free parameters）, making this model in-complete, inconsistent and unnatural. Hence, SM is far away from an ultimate theory buta low energy effective theory of more fundamental physics at higher energy scale. Basedon this, further in-depth study about new physics theories beyond the SM, explorationof the electroweak symmetry breaking mechanism and the origin of quality become theprimary tasks in particle physics nowadays. With the successful operation of the largehadron collider（LHC） at CERN, a great quantity of experimental data are collected andanalyzed. The particle physics research has entered into the new era of “TeV”. In July2012, ATLAS and CMS both claimed the discovery of a new particle, Higgs boson like,making the most significant breakthrough in particle physics over the last four decades.In this thesis, two of the new physics models beyond the SM are discussed–221model and top-flavor seesaw model.221model and Type-I top-flavor seesaw model havesimilar gauge structure SU（2） SU（2） U（1） but different fermion formulation, whileType-II top-flavor seesaw mode takes different gauge group SU（2） U（1） U（1）. Thisthesis mainly focus on the following topics:New model building, system analysis about gauge group structure, Lagrange, pa-rameter space；Phenomenology of new gauge bosonW₁^±1in221model on LHC；Phenomenology of Higgs bosons in Type-I and Type-II top-flavor seesaw model onLHC.