Constraining parameter space of the Little Higgs model by data of tera-Z factory and ILC

Abstract

The Standard Model prediction on the forward-backward asymmetry for $b\bar{b}$ production ($A_{FB}^b$) is well consistent with the data of LEP I at the Z-pole, but deviates from the data at $\sqrt{s}=8993$ GeV which are slightly away from the pole. This deviation implies that there still is room for new physics. We calculate the $A_{FB}^b$ at vicinity of Z-pole in the Little Higgs Model as well as other measurable parameters such as $R_b$ and $R_c$, by which we may constrain the parameter space of the Little Higgs Model. This can be tested in the newly proposed tera-Z factory. With the fitted parameters we further make predictions on $A_{FB}^b$ and $A_{FB}^t$ for $t\bar{t}$ production at the ILC energy.

Comments: 18 pages, 8 figures and 3 tables. Radical changes including the title of the work are made and more reference added