Forward-Backward Asymmetry in Top-Quark Production inpp¯Collisions ats=1.96TeV

We present measurements of the forward-backward charge asymmetry in top pair production using $1.9{\mathrm{fb}}^{-1}$ of $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ recorded with the Collider Detector at Fermilab II. Correcting for acceptance and measurement dilutions we obtain parton-level asymmetries of $A_{\mathrm{FB}}^{p\overline{p}}=0.17\pm 0.08$ in the $p\overline{p}$ frame and $A_{\mathrm{FB}}^{t\overline{t}}=0.24\pm 0.14$ in the $t\overline{t}$ frame. The values are consistent with the standard model expectation and disfavor exotic production mechanisms with significant negative values.