Lepton asymmetries in exclusive b→ sℓ +ℓ − decays as a test of the standard model

Abstract

We argue that the longitudinal lepton polarization and the forward-backward asymmetries in exclusive B→(K,K ∗)ℓ +ℓ − decays are largely unaffected by the theoretical uncertainties in the long-distance contributions both induced by the long-range charming penguins in the ℓ +ℓ − channel and those in the meson channels encoded in the meson transition form factors, and are mainly determined by the short-distance Wilson coefficients at the low-energy scale μ≃ m b . Thus, the abovementioned asymmetries provide a powerful probe of the Standard Model and its extensions.