Searching for Flavor-Changing Neutral-Current Signals via e＋e-（γγ） →tcht0 in Topcolor-Assisted Technicolor Model

In the context of the top-color-assisted technicolor （TC2） model, the flavor-changing neutral-current （FCNC） interaction induced by the top-higgs （hOt） are predicted at tree level. We study the relevant processes of e＋e-（γγ）→tcht0 at the International Linear Collider （ILC）. It is found that these rare processes production rates can be enhanced significantly in the TC2 model. Especially for the process γγ→tcht0, the total cross section will reach a few fb in the reasonable parameter space. We also calculate the distributions of transverse momenta, pseudo-rapid and invariant mass of the top-higgs. In view of the main decay modes of top-higgs for mho 〈 2mr, we find that there will be several hundreds FCNC events produced at the ILC with annually integral luminosity of 500 fb-1. Due to the clean background, such FCNC signals can possibly be detected at the ILC.     

ILC上Z玻色子与荷电top-pion对联合产生过程的研究

在国际直线对撞机(ILC)上顶色辅助的人工色(TC2)模型下对Z玻色子与荷电top-pion对联合产生过程e⁺e^- → Zπ_t⁺π_t^-进行了研究. 计算了过程e⁺e^- → Zπ_t⁺π_t^-的产生截面, 发现在TC2模型所允许的参数空间范围之内该过程的截面最大可达到1 fb. 考虑到荷电top-pion的主要的衰变模式π_t⁺ → tb, 发现该截面在ILC能产生很可观的事例数.     

Detection of Charged Higgs Bosons in e~+e~-(γγ)→tφ~- Production at the ILC

In the context of the left-right twin Higgs (LRTH) model,we have studied the charged Higgs bosons production processes e~+e~-(γγ)→tφ~at the International Linear Collider (ILC).It is found that the cross sections of these two processes could reach a few fb with reasonable parameter values.With the yearly integrated luminosity of L=500 fb-1 expected at the ILC,one could collect hundreds up to thousands of charged Higgs events via these two processes.Therefore,our researches in this paper can help us search for charged Higgs bosons,and furthermore,to test the LRTH model.     

Searching for a neutral top-Higgs in association with top-quark pairs at an e~+e~- collider in the TC2 model

We investigate the associated production of the neutral top-Higgs h_t⁰ with a pair of top-quarks in the context of the topcolor-assisted technicolor (TC2) model at the future e⁺e^- Linear Colliders (LC) i.e. e⁺e^- → tt h_t⁰. We calculate the production rate and present the distributions of the transverse momenta of top-Higgs and top-quarks. The results show that the total cross section is typically of the order of 1.0-7.5 fb in the energy range between 1000 GeV and 2000 GeV of the LC for the whole top-Higgs mass region of interest. It should be distinctly possible that hundreds or even thousands of h_t⁰ signals can be produced per year at the LC given the luminosity L=500 fb^-1.