High-energy Collider To Detect The Possibility Of Top Meson

The standard model(SM) of elementary particle describes strong and elec-troweak interactions. The mechanism of electroweak symmetry breaking(EWSB) remains an open question in current physics despite the SM which has been extensively tested by the high energy experimental data during the past 40 years. Furthermore, in the SM, elementary Higgs field is assumed to be responsible to the EWSB, the scalar sector suffers from the problem of triviality and unnaturalness, etc . SM isn't perfect theory, it can only be effective field theory . There must have new physics beyond the SM. So people provided some new physics models. For example, the supersymmetry(SUSY) theory, topcolor assisted technicolor(TC2) model and so on. Now TC2 model is very prevail.In this paper, we calculate the contributions of the FCS coupling Ï€_t⁰tc to the processes gc â†' tγ and gc â†' tZ in the framework of TC2 models, and see whether the effects of the FCS coupling Ï€_t⁰tc on tγ and tZ production can be detected at the Tevatron and the LHC experiments.For 200GeV ≤ m_Ï€t ≤ 400GeV and 0.02 ≤ ε ≤ 0.08, the cross sections of tγ and tZ production at the Tevatron are in the ranges of 1.2 × 10^-4pb 2.1 × 10^-3pb and 8.8 × 10^-4pb 5.4 × 10^-3pb, respectively. If we assume the yearly integrated luminosity (?)int = 2fb-1 for the Tevatron , then the number of the yearly production events is smaller than 10 . Thus, it is very difficult to detect the effects of the FCS coupling Ï€_t⁰tc on the tγ and tZ production at the Tevatron experiments. However, it is not this case for the future LHC experiment . There will be 3.1 × 10⁵ 5.1 × 10⁴ tγ events and 6.1 × 10⁵ 1.0 × 10⁵ tZ events to be generated per year.Second, in the context of TC2 models, we study the production of the top-pions Ï€_t^0,± with single top quark via the processes pp â†' tÏ€_t⁰ + X and ppâ†' tÏ€_t^- +X, and discuss the possibility of detecting these new particles at Tevatron and LHC. We find that it is very difficult to observe the signals of these particles via these processes at Tevatron, while the neutral and charged top-pions Ï€_t⁰ and Ï€_t^± can be detecting via considering the same sign top pair (ttc or ttc) event and the ttb event at LHC, respectively.At last, we study the contributions of the neutral top-pion Ï€_t⁰ to the LFV processes μ⁺μ^-â†'τμ ( or Ï„e), γγâ†' τμ (or re), e⁺e^- â†'τμ, and eγâ†' eÏ€_t⁰â†' eτμ(e) via the flavor changing (FC) couplings Ï€_t⁰lilj and discuss the possibility of searching for the LFV signals via these processes in future lepton colliders.taking into account the constrains of the present experimental limit of the LFV process μâ†'eγ on the mixing factor k and assuming 150GeV ≤ m_Ï€t < 180GeV, we find that the cross sections of the LFV processes μ⁺μ^- â†'τμ and e⁺e^- â†' γγ â†'τμ can reach 1.5 × 10²fb and 8.3 × 10^-2fb, respectively, which cannot be detected in future experiments.