Rare B decays and Tevatron top-pair asymmetry

Abstract

The recent Tevatron result on the top quark forward-backward asymmetry, which deviates from its standard model prediction by 3.4$\ddot{I}ƒ$, has prompted many authors to build new models to account for this anomaly. Among the various proposals, we find that those mechanisms which produce $t\bar{t}$ via $t$- or $u$-channel can have a strong correlation to the rare B decays. We demonstrate this link by studying a model with a new charged gauge boson, $W^{\prime }$. In terms of the current measurements on $B\to \ddot{I}€K$ decays, we conclude that the branching ratio for $B^{-}\to \ddot{I}{€}^{-}{\bar{K}}^0$ is affected most by the new effects. Furthermore, using the world average branching ratio for the exclusive B decays at $2\ddot{I}ƒ$ level, we discuss the allowed values for the new parameters. Finally, we point out that the influence of the new physics effects on the direct CP asymmetry in B decays is insignificant.

15 page, 6 figures, typos corrected and references added, final version to appear journal