STYLE=“word-wrap： break-word”〉The Standard Model（SM） prediction on the forward-backward asymmetry for bˉb production（A^bFB） is well consistent with the data of LEP at the Z-pole, but deviates from the data at...STYLE=“word-wrap： break-word”〉The Standard Model（SM） prediction on the forward-backward asymmetry for bˉb production（A^bFB） is well consistent with the data of LEP at the Z-pole, but deviates from the data at√s =89.55 and 92.95 Ge V which are slightly away from the pole. This deviation implies that there is still room for new physics. We calculate the A^bFB at the vicinity of the 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 further tested in the newly proposed tera-Z factory. With the fitted parameters we further make predictions on A^bFB and A t FB for tˉt production at the International Linear Collider（ILC）.展开更多
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(11275036,11047002,11375128)Fund of Natural Science Foundation of Hebei Province(A2011201118)Natural Science Fund of Hebei University(2011JQ05,2007113)
文摘STYLE=“word-wrap： break-word”〉The Standard Model（SM） prediction on the forward-backward asymmetry for bˉb production（A^bFB） is well consistent with the data of LEP at the Z-pole, but deviates from the data at√s =89.55 and 92.95 Ge V which are slightly away from the pole. This deviation implies that there is still room for new physics. We calculate the A^bFB at the vicinity of the 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 further tested in the newly proposed tera-Z factory. With the fitted parameters we further make predictions on A^bFB and A t FB for tˉt production at the International Linear Collider（ILC）.
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.
