Topcolor Assisted Technicolor Model Predicted Boson And The Lhc Top Quark Pair Production

The standard model (SM) is one of the greatest achievements in particle physics, and it tested by the high energy experimental data. However, SM still suffers some theoretical problems of being unable to explain EWSB's root, too many free parameters, triviality, and unnaturalness, etc. In addition, SM thinks neutrinos is not the quality, but it has little and resonances. Therefore, SM can only be an effective theory below some high energy scale. There may be new physics beyond the SM. So, people started to explore the positive and proposed some new physics:The little Higgs theory, Supersymmetry theory and Technicolor theory. People are very interested in Technicolor theory now, TC2 model is considered to be one of the candidates of the new physical models.At first, we consider the contributions of the scalar particles(Ï€t±, ht0, ht0 and htc) predicted by the topcolor scenario to the tt production at the LHC. The results show that we have taken cm. energy (?)=14TeV, the correction effects of the new scalars to the tt production cross section are significant large. The value of the relative correction parameter R1 is larger than 10%, which might be detected at the LHC. Then we consider the spin correlation in the process of the top quark decay. For 200GeV≤M≤450GeV and 0.03≤ε≤0.09, the values of the relative correction parameter R2 is in the range of 14%-29%. At the same time, we calculate the relative corrections to the top quark transverse momentum distribution and inviriantmass distribution, their relative correction parameters are R3 and R4. For the masses of the scalars equaling to 300GeV andε=0.05, the values of the relative correction parameters R3 and R4 are in the ranges of 9%～52% and 10%-17%, respectively.In addition, we consider the color-octet strong gauge boson Bαand the colorless neutral weak gauge boson Z'predicted TC2 model. They contribut to qqâ†'tt processes at the LHC. We calculate the top pair production at the LHC and detect some observations. When k=1.5 and the mass of BαMB=600GeV, the relative correction of Bαto the top pair production cross section can reach 8.2%. When k1=0.3 and the mass of Z'Mz'= 600GeV, the relative correction of Bαto the top pair production cross section can reach 2.8%. Second, we consider the spin correlation in the process of the top quark decay. When k=1.5, MB=600GeV and k1=0.3 Mz'=l000GeV, the relative corrections of Bαand Z' to ratio of the tt spin correlation can approach 7.9% and 2.5%, respectively. Finally, we also calculate the relative correction to the top quark inviriant mass distribution Mtt- When k=2.0, Mtt-=550GeV and MB=500GeV, the relative correction of Bαto the top pair inviriant mass distribution can reach 8.2%. When k1=0.5, MZ'=500GeV and Mtt-=550GeV, the relative correction of Z' to the top pair inviriant mass distribution can reach 2.9%.