In the context of the topcolor-assisted technicolor （TC2） model, we consider the production of the neutral scalar S （7~t~ or ht~） associated with a photon at the LHC and compare our results with those given by the minimal supersymmetric extension of the Standard Model （MSSM）. We find that its production cross section is larger or smaller than that of the scalar particle predicted by the MSSM model, depending on the values of the relevant free parameters.
Considering the process pp→VH ＋X（V = W or Z） is a significant channel for searching for a light Higgs boson, we calculate the contributions of the littlest Higgs model with T-parity （called LHT model） to its production cross section. We find that, in most of the parameter space, the value of the relative correction parameter R is very small. However, with reasonable values of the free parameters, its value can be significantly larger.
Motivated by recent search results for the standard model （SM） Higgs boson at the Large Hadron Collider （LHC）, we revisit the Higgs phenomenology in the littlest Higgs model with T-parity （LHT）. We present the signal strength modifier ix, respectively, for the main search channels qq＇→ jjh → jjγγ, qq＇→Vh →Vγγ, qq＇→Vh→ Vbb, gg→ h→ γγ, and gg→h→ VV in the LHT model. It is found that an enhancement factor of 1.09-1.56 in the qq＇→jjh→jjγγ channel can be obtained for this model in Case B with parameter f in the range 500 1000 GeV. However, the rates for bb, ττ are significantly suppressed relative to the SM predictions, which are still consistent with the current sensitivity. It is hoped that this will be further tested with larger integrated luminosity at the LHC.
The left-right twin Higgs （LRTH） model predicts the existence of the neutral Higgs bosons （h, φ0）, which can be produced in pairs （φ0φ0, hh, φ0h） via γγ collisions at the next generation e＋eInternational Linear Collider （ILC）. Our numerical results show that the production cross section of the neutral Higgs boson pair φ0φ0 can reach 8.8 fb. The subprocess γγ → φ0φ0 might be used to test the LRTH model in future ILC experiments.
The new particles predicted by the littlest Higgs model with T-parity (called LHT model) can induce the lepton flavor violation (LFV) couplings at the one-loop level,which can add contributions to some LFV processes.Taking into account the constraints of the experimental data on the relevant free parameters,we calculate the branching ratios of the LFV decay processes Z → l ˉl and τ-→μ-P 1 P 2 with P 1 P 2 = π + π-,K + K-,and K0 ˉK 0 in the context of this new physics model.We find that the LHT model can indeed make significant contributions to some of these LFV decay processes.The Z factory option for the future high energy e + e-collider experiments will give severe constraints on the LHT model.
YUE ChongXing,MA Wei,ZHANG TingTing,LIU Wei & LIU JinYan Department of Physics,Liaoning Normal University,Dalian 116029,China
