Lepton asymmetries in exclusive $b\to s{\ell }^{+}{\ell }^{-}$ decays as a test of the Standard Model

Abstract

We argue that the longitudinal lepton polarization and the forward-backward asymmetries in exclusive $B\to (K,K^{\ast }){\ell }^{+}{\ell }^{-}$ decays are largely unaffected by the theoretical uncertainties in the long-distance contributions both induced by the long-range charming penguins in the ${\ell }^{+}{\ell }^{-}$ 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 $\mu \simeq m_b$. Thus, the above mentioned asymmetries provide a powerful probe of the Standard Model and its extensions.

Comments: revtex, 9 pages, 5 figures