The forward-backward asymmetry in top-pair production that was observed in 2008 gets a boost in a recent CDF publication. Not only has the forward-backward asymmetry been further confirmed, but also distributional preferences are shown. Strikingly, the forward-backward asymmetry is the most sizable in the large $M_{t\overline{t}}$ invariant mass region and in the large rapidity difference $|\Delta y|$ region. Here we used our previously proposed $t$-channel exchanged $W^{\prime }$ boson to explain the new observations. We show that a new particle exchanged in the $t$ channel generically gives rise to such observations. Furthermore, we show that the proposed $W^{\prime }$ can be directly produced in association with a top quark at the Tevatron and the LHC. We perform a signal-background analysis and show that such a $W^{\prime }$ is readily observed at the Tevatron with a $10{\mathrm{fb}}^{-1}$ luminosity and at the LHC-7 with just a $100{\mathrm{pb}}^{-1}$ luminosity.

• Received 12 January 2011

DOI:https://doi.org/10.1103/PhysRevD.83.074006