Study Of T-odd Top Quark Partner At The LHC In The LHT Model

The standard model is a very successful effective theory,it contains 61 elementary particles and describes the interactions between them.In 2012,the last particle(Higgs boson)predicted by the standard model was discovered,which indicates that all particles contained in the standard model were experimentally verified.So far,there is no substitute for the standard model.However,the standard model still has some defects to be solved,such as the asymmetry between matter and antimatter,dark matter and dark energy,and fine tuning.Therefore,we still need to constantly search for new models or improve the standard model to solve these problems.In order to solve the fine tuning problem,many solutions have been proposed.The Littlest Higgs model solved this problem very well by introducing new heavy gauge bosons,vector-like top quark partner and scalar particles.However,these new particles coupled to the standard model particles raise a new problem,that is,the Littlest Higgs model is strongly limited by precision electroweak measurement.So,a discrete symmetry T-parity based on the Littlest Higgs model is introduced to solve the strong limitation from precision electroweak measurement,this is called the Littlest Higgs model with T parity(LHT).The LHT model predicts two vector-like top quark partners,which are T-even and T-odd particle,respectively.In this thesis,we study the production of T-odd top quark partner that can 100% decay to the top quark and the lightest T-odd particles()at the Large Hadron Collider(LHC).Taking into account the current limits,we mainly studied the T-odd top quark partner by the double lepton process ? ? ? at 14 TeV LHC.The lightest T-odd particle could serve as a candidate for dark matter.We use ?, and 8)as important observations to analyze the signal of the T-odd vector-like top quark partner.We analyze the signal significance and find that the lower limit on the T-odd top partner masses are about 1.04 TeV,1.14 TeV,1.23 TeV at 2? confidence level at 14 TeV LHC with the integrated luminosity of 30 fb,100 fb,300 fb.If we use 1000(3000)fb of the integrated luminosity,the lower limit can be raised to about 1.34(1.44)TeV.