Studying Production Signal Of New Bosons Beyond Standard Model And Their Properties At LHC

Testing the standard model (SM) precisely and searching for the new physics beyond standard model are the driving forces behind the undergoing experiments at CERN the large hadron collider (LHC). Although the standard model of particle is extremely successful in explanation of the high energy experiments, there are remain-ing problems not well understood, such as neutrino oscillation, dark matter, matter-antimatter asymmetry, hierarchy problem, strong CP problem etc. It is commonly believed that the SM can only be a low energy effective theory of a more fundamental theory, thus various new physics models have been proposed. The stabilization of the Higgs mass at the electroweak scale requires the introduction of new physics at TeV scale. The existence of dark matter also provides an unambiguous evidence of new physics beyond the standard model. New physics models predict the existence of new bosons beyond the standard model. Probing the production of new boson and its prop-erty at LHC is meaningful to confirm the new physics beyond the SM and to identify different new physics models.Supersymmetric model has been a widely studied new physics model, which pre-dicts the existence of the superpartners corresponding to the SM particles. Fine-tuning and experimental Higgs mass bound point to a "golden region" in the minimal super-symmetric standard model (MSSM) parameter space proposed by M. Perelstein and C. Spethmann. The lighter sbottom (b1) particle is a light sfermion in this golden region. We study the sbottom pair production at LHC. With (?)=14TeV, the cross section for sbottom pair production reaches214fb for550GeV sbottom. The sbottom in the golden region, differing from the conventional decay modes b1→bχ10, mainly decays to χ1-t and t1W-. We choose the final state of4jets+1lepton+ET as the sbottom production signature at the LHC. with setting the reasonable kinematical cuts, one can find that a significant level of5-6σ could be reached for the lighter sbottom discovery at the LHC with100fb-1integrated luminosity. Other TeV-scale bosons W'±and Z' particles are introduced by the extension of the SM gauge groups. We study the W'W H interaction in the new physics models. It is found that the existence of W'RW H interaction in left-right symmetric model, while the W'LW H interaction can be found in the other new physics models. We investigate the W' production process at the LHC. The W H production rates have been enhanced around the region of (?)～mw'. The angular distribution of charged lepton can be used to distinguish W'RW H from W'LW H in the pp→HW→bblv process at the LHC. In order to suppress the standard model backgrounds, we set the intermediate resonance constraints to highlight the signal process. We define a new type forward-backward asymmetry AFB relating to the angle between the direction of the charged lepton in the W rest frame and that of the final system. We find that AFB can reach0.03(-0.07) for W'R (W'L) production at(?)=14TeV.Searching for Higgs particle is one of the most important goals at the LHC. The two Higgs doublet model predicts the existence of charged Higgs particles. The in-vestigation of charged Higgs boson through its hadronic decay is always a tough issue for suffering from large QCD backgrounds at the LHC. We investigate the production and decay process of the charged Higgs particle. It shows that heavier than500GeV charged Higgs associated with W boson production can be found via pp→W±H(?)→l+ET+bbjj process at the LHC with its hadronic decay channel H±→tb(bt). Com-paring the production process of W±H(?) with that of W±W'(?) at the LHC, one can find the angular distribution of the b-jet decayed from H±and W'±can be used to identify the charged scalar from vector bosons.