Phenomenological Studies Of The New Gauge Bosons From Little Higgs Theory

Content:Although the standard model(SM) has passed a lot of precision experiemntal tests, it still suffers some theoretical problems and some deviations from experimental data. People usually take the view that the SM is a low energy effective theory and it will be modified by the new physics at a higher scale.As a new physics idea, little Higgs has been proposed and many explicit models has been costructed. We categorize the little Higgs models into "product group" models and "simple group" models. As representatives of the two classes, detailed phenomeno- logical studies of the littlest Higgs model (LH model) and SU(3) simple group model (SU3LH) can reflect many general phenomenological features of little Higgs models. LH model and SU3LH model predict some new particles which may be produced and detected by future collider experiments, such as Large Hadron Collider (LHC) and International Linear Collider (ILC).In the context of the little Higgs models, we discuss single production of the new charged gauge bosons in association with top quark at the LHC. We find that the new charged gauge bosons W(?) and X~-, which are predicted by the littlest Higgs modeland the SU(3) simple model, respectively, can be abundantly produced at the LHC. However, the values of the ratios N_W and N_X are very small in most of the parameter space. It is only possible to detect the signal of W(?) via the process pp→gb + X→tW_? + X at the LHC in a small region of the parameter space.Littlest Higgs model with T-parity predicts the existence of the neutral, weakly interacting, new gauge boson B_H, which can be seen as an attractive dark matter can- didate. We study the production of B_H via eΥand ep collisions. We find that the new gauge boson B_H can be abundantly produced via the subprocesses e~-Υ→L~-B_H andΥq→B_HQ. We further estimate the ratio of the signal over the square of the back- ground R_L and R_Q and find the value can reach the observable threshold of the high energy linear e~+e~- collider and THERA collider experiments.