Study Of Single Production Of T_+ At The Ep Colliders In The LHT Model

The great success of the Standard Model(SM)comes from its natural interpretation of experimental results and correct predictions of unknown physics.The discovery of Higgs boson in 2012 provided more material for studying the mechanism of the electroweak symmetry spontaneous breaking.But the fine tuning problem of the SM has still plagued the theorists.As one of the solutions to this problem,the Littlest Higgs Model with T parity(LHT)has been proposed.In addition,new heavy particles such as the top partner are predicted in the LHT model.Although the current experiments still allows the LHT model to solve the fine tuning problem naturally,the new physics effects predicted by the LHT model have not been observed yet.In this paper,we first give a short review of the SM and the LHT model,then briefly introduces some basic knowledge of the collider physics.On these bases,we studied the single production of vector-like T-even top partner(T+)decaying to Wb in the leptonic channel at ep colliders in LHT model.We selected two ep collider schemes,LHeC with (?)=1.98TeV and FCC-eh with(?)=5.29TeV,to calculate the cross sections of single T+ production varies with two free parameters f and R in the case of non-polarized initial electron beams.It was then found that if the left-hand polarization of the initial electron beams reached 80%,the scattering cross sections could be increased to 1.8 times that of the non-polarized initial state.After that,we analyzed the main SM backgrounds of the signal.Finally,we selected a set of cuts according to the characteristics of the signal to improve the signal’s statistical significance.And then obtained the detection capability of the LHeC and the FCC-eh to the T+ with 2σ level.The results show that the detec-tion capability of the LHeC does not exceed the existing experimental limits from the electroweak precision observables and Higgs data.But when the integrated luminosity of FCC-eh reaches 100 fb-1,1000 fb-1,3000 fb-1,the lower limit of mass can be pushed to 1350 GeV,1500 GeV and 1565 GeV,respectively,which will give stronger limits than the current experiments.If we further think about the HL-LHC withy(?)=14TeV and L=3000fb-1,our results show that the LHT model is still a natural solution to the short-comings of the electroweak and scalar sector although it has been constrained severely.