Charming new physics in rare B decays and mixing?

Abstract

We conduct a systematic study of the impact of new physics in quark-level b→cc̄s transitions on B physics, in particular rare B decays and B-meson lifetime observables. We find viable scenarios where a sizable effect in rare semileptonic B decays can be generated, compatible with experimental indications and with a possible dependence on the dilepton invariant mass, while being consistent with constraints from radiative B decay and the measured Bs width difference. We show how, if the effect is generated at the weak scale or beyond, strong renormalization-group effects can enhance the impact on semileptonic decays while leaving radiative B decay largely unaffected. A good complementarity of the different B-physics observables implies that precise measurements of lifetime observables at LHCb may be able to confirm, refine, or rule out this scenario.