  We present the first measurement of the integrated forward-backward charge
asymmetry in top-antitop quark pair (ttbar) production in proton-antiproton
collisions in the lepton plus jets final state. Using a b-jet tagging algorithm
and kinematic reconstruction assuming ttbar+X production and decay, a sample of
0.9fb-1 of data, collected by the D0 experiment at the Fermilab Tevatron
Collider, is used to measure the asymmetry for different jet multiplicities.
The result is also used to set upper limits on ttbar+X production via a Z'
resonance.
