Probing New Physics in $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ decays

Abstract

We study the exclusive decays of $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ by the results in the perturbative QCD with the heavy quark effective theory and lattice calculations. We obtain the form factors for the $B\to K^{(\ast )}$ transitions in the whole allowed region. Our predictions on the branching ratios of $B\to K{\ell }^{+}{\ell }^{-}$, $B\to K^{\ast }{e}^{+}{e}^{-}$, and $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ are $0.53\pm 0.05_{-0.07}^{+0.10}$, $1.68\pm 0.17_{-0.09}^{+0.14}$, and $1.34\pm 0.13_{-0.06}^{+0.11}\times 10^{-6}$, where the errors are from the quark mixing elements and hadronic effects, respectively. We also find that our definitions of the T-odd observable and the up-down asymmetry of the $K$ meson in $B\to K^{\ast }{\ell }^{+}{\ell }^{-}\to K\pi {\ell }^{+}{\ell }^{-}$ can be used to probe new physics.

Comments: 20 pages, 6 Figures, LaTex file