Rare B decays in a single Universal Extra Dimension scenario

Abstract

Exclusive rare $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$, $B\to K^{(\ast )}\nu \bar{\nu }$ and $B\to K^{\ast }\gamma$ decays are studied within the Applequist-Cheng-Dobrescu model, an extension of the Standard Model in presence of universal extra dimensions. In the case of a single universal extra dimension compactified on a circle of radius R, we study the dependence of several observables on 1/R, and discuss whether the hadronic uncertainty due to the form factors obscures or not such a dependence. We find that, using present data, it is possible in many cases to put a sensible lower bound to 1/R, the most stringent one coming from $B\to K^{\ast }\gamma$.

LaTeX, 4 pages, 4 figures. Talk given at "QCD 06", July 3-7 2006, Montpellier (France)