Probing anomalous tWb interactions with rare B decays

TL;DR

This paper investigates how anomalous top-W-b interactions influence rare B meson decays and oscillations, providing indirect bounds that surpass current collider constraints and predicting potential future observable effects.

Contribution

It offers a combined analysis of rare B decay observables to set new indirect bounds on anomalous t-W-b couplings, surpassing existing collider limits.

Findings

Indirect bounds on anomalous t-W-b couplings are stronger than direct collider constraints.

Predicted effects in B_s->μ^+μ^- and B->K^{(*)}νar{ν} decays could be observed with future measurements.

Future precision in B decay observables can further tighten constraints on anomalous top interactions.

Abstract

Precision studies of top quark properties are currently underway at the LHC and Tevatron colliders with the prospect of probing anomalous t-W -b interactions. In the mean time, recent experimental results for the B_{d,s} - \bar{B}_{d,s} oscillation observables, the branching ratio B_s->\mu^+\mu^-, as well as the forward - backward asymmetry in B->K\starl^+l^-, accompanied by the accurate theoretical predictions for the relevant observables obtained within the SM motivate a combined study of these observables in the presence of anomalous t - W - b vertices. We investigate contributions of such anomalous couplings to the B->X_s l^+l^- decay mode, and combining them with the modifications of the B_{d,s} - \bar{B}_d,s, B->X_s{\gamma} observables, we determine indirect bounds on the real and imaginary parts of the anomalous t - W - b interactions. We find these to be mostly superior to present direct constraints coming from top decay and production measurements at the LHC and Tevatron. Finally, we predict the allowed effects in the branching ratios of the B_s->\mu^+\mu^- and B->K^{(*)}\nu \bar{\nu}, as well as the forward-backward asymmetry in B->K^*l^+l^-. We find that improved knowledge of these observables in the future could further constrain some of the anomalous tWb interactions.