Top quark forward-backward asymmetry in the little Higgs model

A sizable difference in top quark pair forward backward asymmetry (AFB) is observed at Tevatron. The discrepancy triggers many new physics beyond the standard model (SM) and then constrains the parameter spaces in them. In this article we calculate the AFB of the top-pair production at Tevatron up to next to leading order (NLO) in the little Higgs model (LHM). We find that the contribution of Z(H) can be large enough to make up the gap between SM prediction and experimental data. Then, the parameter space for the couplings between Z(H) and quarks are constrained. Thus, this model can fulfill the experimental data, both in AFB and in cross section.