Exclusive $B-->\pi {\mathrm{\ell }}^{+}{\mathrm{\ell }}^{-}$ and $B-->\rho {\mathrm{\ell }}^{+}{\mathrm{\ell }}^{-}$ Decays in the Universal Extra Dimension

We investigate the influence of the universal extra dimension on the branching ratio in the $B\to \pi (\rho ){\mathrm{\ell }}^{+}{\mathrm{\ell }}^{-}$ decay. Taking $1/R\sim {200-1000}$GeV with one universal extra spatial dimension, which is consistent with the experimental data for $\mathcal{B}(B\to X_s\gamma )$, ${\cal B}(B \to K^\ast \mu^+\mu^- $) and the electroweak precision tests, we obtain that for both ($\mu ,\tau$) channels the branching ratio strongly depends on the compactification radius 1/R.