Top forward-backward asymmetry in chiral U(1)' models
  We construct flavor-dependent chiral U(1)' models with a Z' boson which couples to the right-handed up-type quarks in the standard model (SM). To make the models have realistic renormalizable Yukawa couplings, we introduce new Higgs doublets with nonzero U(1)' charges. Anomaly-free condition can be satisfied by adding extra chiral fermions. We show that these models could analyze the discrepancy between the SM prediction and empirical data in the top forward-backward asymmetry at the Tevatron. 
P. Ko, Yuji Omura, Chaehyun Yu (KIAS)
hep-ph hep-ex