A Natural origin for the LHCb anomalies

TL;DR

The paper proposes that the LHCb anomalies in B-meson decays can be explained by a warped extra-dimensional model where new physics arises naturally from Kaluza-Klein excitations, linking flavor anomalies to electroweak corrections.

Contribution

It demonstrates that warped extra-dimensional models with composite fermions can naturally account for flavor anomalies and predict observable deviations in electroweak and flavor-changing processes.

Findings

Flavor anomalies can be reproduced with composite bottom and muon fields.

Predicted deviations in Z-boson couplings are close to current experimental bounds.

Model links flavor anomalies to electroweak precision observables.

Abstract

The anomalies recently found by the LHCb collaboration in $B$-meson decays seem to point towards the existence of new physics coupled non-universally to muons and electrons. We show that a beyond-the-Standard-Model dynamics with these features naturally arises in models with a warped extra-dimension that aim to solve the electroweak Hierarchy Problem. The attractiveness of our set-up is the fact that the dynamics responsible for generating the flavor anomalies is automatically present, being provided by the massive Kaluza--Klein excitations of the electroweak gauge bosons. The flavor anomalies can be easily reproduced by assuming that the bottom and muon fields have a sizable amount of compositeness, while the electron is almost elementary. Interestingly enough, this framework correlates the flavor anomalies to a pattern of corrections in the electroweak observables and in flavor-changing processes. In particular the deviations in the bottom and muon couplings to the $Z$-boson and in $\Delta F = 2$ flavor-changing observables are predicted to be close to the present experimental bounds, and thus potentially testable in near-future experiments.