Top-Quark Forward-Backward Symmetry

Abstract

Top-quark pair production at the Tevatron is discussed within the Randall-Sundrum model of warped extra dimensions. Generically, the exchange of massive Kaluza-Klein gluons has the potential to generate a large forward-backward asymmetry. In models with an anarchic flavor structure, however, their coupling to the light quarks inside the proton is strongly suppressed. The consequent suppression of the asymmetry at tree level is lifted at next-to-leading order. Still, it is not possible to increase the forward-backward asymmetry with respect to the Standard-Model prediction in this framework.