Exclusive $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$, $B\to K^{(\ast )}\nu \bar{\nu }$ and $B\to K^{\ast }\gamma$ transitions in a scenario with a single Universal Extra Dimension

Abstract

We analyze the exclusive rare $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$, $B\to K^{(\ast )}\nu \bar{\nu }$ and $B\to K^{\ast }\gamma$ decays in the Applequist-Cheng-Dobrescu model, which is an extension of the Standard Model in presence of universal extra dimensions. In particular, we consider the case of a single universal extra dimension. We study how spectra, branching fractions and asymmetries depend on the compactification parameter 1/R, and 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 $B\to K^{\ast }\gamma$. We also study how improved experimental data can be used to establish stronger constraints to this model.

Comments: RevTex, 26 pages, 12 figures