title: Top quark forward-backward asymmetry and same-sign top quark pairs.
abstract: The top quark forward-backward asymmetry measured at the Tevatron collider shows a large deviation from standard model expectations. Among possible interpretations, a nonuniversal Z' model is of particular interest as it naturally predicts a top quark in the forward region of large rapidity. To reproduce the size of the asymmetry, the couplings of the Z' to standard model quarks must be large, inevitably leading to copious production of same-sign top quark pairs at the energies of the Large Hadron Collider (LHC). We explore the discovery potential for tt and ttj production in early LHC experiments at 7-8 TeV and conclude that if no tt signal is observed with 1 fb⁻¹ of integrated luminosity, then a nonuniversal Z' alone cannot explain the Tevatron forward-backward asymmetry.
authors.affiliation: High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA. berger@anl.gov
authors.forename: Edmond L
authors.initials: EL
authors.lastname: Berger
authors.forename: Qing-Hong
authors.initials: QH
authors.lastname: Cao
authors.forename: Chuan-Ren
authors.initials: CR
authors.lastname: Chen
authors.forename: Chong Sheng
authors.initials: CS
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang