With T-parity Minimal Higgs Model And The Top Quark At The Lhc

Content:As one of the greatest achievements in theoretical physics in 20th century, standard model(SM) describes strong, weak and electromagnetic interactions and has been extensively tested by the high energy experimental data. However, SM still suffers some theoretical problems, such as too many free parameters, triviality, and unnaturalness. So there may be new physics beyond the SM to solve the SM problem mentioned above. The little Higgs theory is considered to be one of the candidates of the new physical theory. However, the low energy electroweak precision tests enforce the symmetry breaking scale f of the LH model to be larger than about 4TeV, which induces that the fine tuning between the cut-off scale and the electroweak scale is needed again. To alleviate this difficulty, so T-parity is introduced and form the LHT model. The LHT model can contribute to the observal of some SM processes, so visa this we can test the new physics.The top quark is the heaviest fermion, which was first found at CDF and D0 experiments. Because of its large mass, the couple constant of top quark with other particle is large, so all the observables relate to top quark is sensitive to new physics. Furthermore, Very large mass of top quark prompts itself to rapidly decay before hadronization and the spin information of the top quark is preserved from its decay. Thus, the top spin configuration can provide additional observables for testing the SM and new physics beyond the SM. Spin correlation in top production and decay is a very interesting issue in top quark physics. It also play an important role in the mechanism of electroweak symmetry breaking (EWSB), and especially new physics connected to EWSB may be found through precision studies of top-quark observables.Our work is based on the LHT model, consider the top quark pair production at the LHC. At the LHC, top quark pair production via process ggâ†'tt and qqâ†'tt. First, we calculate the relative correction of the LHT model to the production cross section Our results show that either the LHC center energy is 10TeV or 14Tev, R1 can reach 0.9. At the same time, we calculate the relative correction to the top quark transverse momentum distribution and inviriant mass distribution, they are and The result show that, both correction are obviously. When 300GeV≤PT≤2000GeV,R2(PT) can reach 0.65, and 500GeV≤mtt≤2000GeV, R3 varies between 0.3-0.3. Secondly, consider the spin correlation in the process of the top quark decay, we calculate the relative correction the result show that when the LHC center energy reach 14TeV, the value of R4 can reach 100%. Finally, to see whether the observables can be measured in the upcoming LHC experiment, we compare our result with the test ability of LHC for one top quark pair event. From this, one can find that our result is in the LHC test ability. And this is important for the LHC experiment test of the Little Higgs theory and LHT model.