$B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ as a probe of Universal Extra Dimensions

Abstract

We study some rare B decays induced by $b\to s$ transition within the Standard Model and in the Appelquist-Cheng-Dobrescu model, which is a New Physics scenario with a single universal extra dimension. In particular, we discuss the dependence on the radius $R$ of the compactified extra-dimension of the branching ratio, the forward-backward asymmetry and the $K^{\ast }$ helicity distributions for the decay modes $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$, with ${\ell }^{-}=e^{-},{\mu }^{-}$, and the tau polarization asymmetries for the mode $B\to K^{\ast }{\tau }^{+}{\tau }^{-}$.

Comments: Talk given at IFAE 2007, Naples, April 11-13. LaTex, 6 pages, 2 eps figures