Study of the forward-backward asymmetry of top quark production in a warped extra dimension model with an extension of the strong interaction

Abstract

The large forward-backward asymmetry of top quark pair production measured by hadron colliders sheds light on new physics signals beyond the Standard Model. In the warped extra dimension model with an additional $SU(3)$ group in the strong sector, we compare the cross section and forward-backward asymmetry of top quark pair production with recent data obtained by CDF and D0. Our numerical analysis shows that the parameter ${c}_{q}\ensuremath{\ge}0.5$, ${c}_{t}\ensuremath{\sim}\ensuremath{-}0.6$, $\mathrm{tan}\ensuremath{\phi}\ensuremath{\ge}20$, and the first excitation of an axial gluon with a mass of about 5--6 TeV can accommodate this large anomaly without violating other experimental constraints. We show that a large ratio of strong couplings ${g}^{D}/{g}^{S}$ sets a strong limit on the parameter space of this model.