We introduce the forward-backward asymmetries Au, Ad corresponding to u¯u, d ¯ d -> t¯t 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.This
work has been supported by projects FPA2006-05294 and
FPA2010-17915 (MICINN), FQM 101, FQM 03048 and
FQM 6552 (Junta de Andalucía)