Top FB asymmetry vs. (semi)leptonic B decays in multi-Higgs-doublet models

TL;DR

This paper explores how multi-Higgs-doublet models can simultaneously explain the top FB asymmetry at the Tevatron and affect semileptonic B decays, analyzing experimental constraints and potential correlations.

Contribution

It introduces a model where scalar bosons influence B decays and top FB asymmetry, highlighting the negligible role of charged Higgs in A^t_{FB} but its significant impact on B decay processes.

Findings

Large flavor-changing Yukawa couplings can enhance A^t_{FB} and B decay rates.

Constraints from BaBar and Belle limit the parameter space for these models.

Possible correlation between top FB asymmetry and B decay anomalies.

Abstract

We investigate the semileptonic and leptonic B decays, B to D^{(*)} tau nu and B to tau nu in our multi-Higgs-doublet models, while keeping in mind the enhancement of the top forward-backward (FB) asymmetry (A^t_{FB}) at the Tevatron. In these models, the extra (pseudo)scalar bosons contribute to A^t_{FB} with large flavor-changing Yukawa couplings involving the top quark, but the contribution of the charged Higgs boson to A^t_{FB} is negligible. However, it may significantly affect B decays: especially, B to D^{(*)} tau nu and B to tau nu. We investigate the constraints on the B decays, based on the recent results in BaBar and Belle experiments, and discuss the possibility that the allowed parameter region in the B decays can achieve large A^t_{FB}.