Little Higgs Theory In E¦Ã, Ep Collider On The Possible Physical Signs

It is well-known that standard model(SM) describes the elementary particles and their phenomenon interaction perfectly. We can say that the framework of the SM is very elegant. So far, there have been many experimentary facts prove that the correctness of the SM. But , the SM can only be an effective field theory below some high energy scale, there are still many deficiencies in SM. There may be new physics beyond the SM. Little Higgs theory is one of the important promising candidates of new physics. The littlest Higgs(LH) model has been constructed based on the ideas of the little Higgs theory, which predicts the existence of new heavy gauge bosons Z_H , B_h and W_h^± and some new scalar particles. These particles might produce characteristic signatures at the present or future collider experiments. In this paper, we study the signatures of these new particles in the future high-energy linear e⁺e^- collider (ILC).We find that the ILC has a large potential for the discovery of new particles. first, we study single production of the SM gauge boson W_s^- and the heavy gauge boson W_H^- via polarized e^-γ collisions in the framework of the LH model. We find that the corrections of the LH model to the cross section σ(W_s^-) might be observed only for the scale parameter f≤ 1.5TeV and the mixing parameter c'≥ 0.4 in the future ILC experiment. However, with a suitably chosen polarization of the initial electron and position beams, the possible signals of the heavy gauge boson W_H^- can be easily detected via e^-γ collisions in the future ILC experiment with S^1/2 = 3TeV and (?)= 500fb^-1.Second, we study single production of vector-like top quark via the process ep â†' ebâ†' v_eT in the future linac-ring type ep (THERA) collider . We find that the production cross section is in the range of 1.2 ×10^-3— 0.48 pb at the THERA with S^1/2 = 3.7 TeV. the cross sections of the single T production at the LHC and the THERA are at the same order of magnitude. Thus, the possible signal of the vector-like top quark T might be detected in the future THERA experiments.Finally, we study the process of e^-γâ†' e^-H. Because of the non-decoupling properties of the Higgs boson, the effective couplings Hγγ and HZγ are sensitive to the contributions of new particles running in the loops. We find that the LH model can produce significant corrections to the production cross section of the process e^-γâ†' e^-H in most of the parameter space allowed by the electroweak precision data. With reasonable values of the free parameters, the absolute value of the relative correction parameter R is larger than 5%, which might be detected in the future ILC experiments.In a word, in the framework of the LH model, we have studied the signatures of the new particles, which can provide theoretic evidence for the future detecting the new particles and testing the correctness of the LH model via eγ, ep collisions in the future ILC experiments.