Studies On Heavy Scalar At The LHC

Since the establishment of standard model in particle physics,all of our known fundamental particles have been classified,and it have described electromagnetic interaction,weak interaction and strong interaction very well.In 2012,the final block of standard model building has been found after the European Center for Nuclear Research(CERN)discovered the Higgs(Higgs)particle predicted in the standard model(SM).Although the standard model does not conflict with the current cosmology knowledge and the experimental data of the collider,there are many unexplained problems in the standard model itself.In view of this,the physicists think that the standard model is an effective theory near the electroweak scale.In order to solve many problems existing in the standard model,many new physical models emerge as the times require.And there are some new physical models that often exists additional scalar particles,which have the same spin,parity and quantum number as the standard model Higgs,but with a heavy amss.In general,it has a mixed effect with the SM Higgs.Suppose there exist a scalar particle s,and it mixed with the SM Higgs particles,then there are two mass eigenstates,h1 and h2.If we define one of the eigenstate h1 as the SM-like Higgs,and the mass is 125 GeV,then the scalar h2 would be a heavier scalar.Moreover,h2 is similar to SM Higgs,it also has coupling effect with the standard model fermions.In this thesis,we discuss the phenomenology of such heavy scalar under Hadron Collider 14 TeV LHC.And in this thesis,the main production channel that we choose is vector boson fusion(VBF),and the main decay mode is through diboson decay to lepton final sate.By simulating the signal and the standard model background of h2? WW?lvlv h2 ? ZZ ? 2l2v and h2? WW lvqq,we analyzed the detection prospects of the scalar h2 with mass range from 200 GeV to 1000 GeV.Considering the different mixing intensity of each reaction path,we found that the double W boson decay path is more capable of finding and removing.For example,while the mixing angle satisfies sin2?=0.04,its exclusion limit can reach 539 GeV and 937 GeV for with the integral luminosity of 300 fb-1 and 3000 fb-1.