We present a new measurement of the inclusive forward-backward tt production asymmetry and its
rapidity and mass dependence. The measurements are performed with data corresponding to an integrated
luminosity of 5:3 fb1 of pp collisions at ffisffiffi
¼ 1:96 TeV, recorded with the CDF-II Detector at the
Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the tt
rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and t.
In the tt rest frame, the asymmetry is observed to increase with the tt rapidity difference, y, and with
the invariant mass Mtt of the tt system. Fully corrected parton-level asymmetries are derived in two