Collider-independent t tbar forward-backward asymmetries

Abstract

We introduce the forward-backward asymmetries A_u, A_d corresponding to u ubar, d dbar -> t tbar production, respectively, at hadron colliders. These are collider- and center-of-mass-independent observables, directly related to the forward-backward and charge asymmetries measured at the Tevatron and the LHC, respectively. We discuss how to extract these asymmetries from data. Because these asymmetries are collider-independent, their measurement at these two colliders could elucidate the nature of the anomalous forward-backward asymmetry measured at the Tevatron. Our framework also shows in a model-independent fashion that a positive Tevatron asymmetry exceeding the standard model expectation is compatible with the small asymmetry measured at the LHC.

RevTeX 5 pages. Extended discussion about A_FB vs A_C, several clarifications, references added. Version to appear in PRL