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...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 ZH can be large enough to make up the gap between SM prediction and experimental data. Then, the parameter space for the couplings between ZH and quarks are constrained. Thus, this model can fulfill the experimental data, both in AFB and in cross section.展开更多
基金Supported by National Natural Science Foundation of China(10975027,11275036,11047002)Natural Science Foundation of Hebei Province(A2013201277,A2011201118)+2 种基金Natural Science Fund of Hebei University(2011JQ05,2007113)open project of State Key Laboratory of Mathematics-Mechanization(Y3KF311CJ1)Natural Science Fund of Hebei University(2011JQ05,2012-242)
文摘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 ZH can be large enough to make up the gap between SM prediction and experimental data. Then, the parameter space for the couplings between ZH and quarks are constrained. Thus, this model can fulfill the experimental data, both in AFB and in cross section.
