QCD Sum Rule Analysis of the Decays $B\to K{\ell }^{+}{\ell }^{-}$ and $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$

Abstract

We use QCD sum rules to calculate the hadronic matrix elements governing the rare decays $B\to K{\ell }^{+}{\ell }^{-}$ and $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ induced by the flavour changing neutral current $b\to s$ transition. We also study relations among semileptonic and rare $B\to K^{(\ast )}$ decay form factors. The analysis of the invariant mass distribution of the lepton pair in $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ and of the angular asymmetry in $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ provides us with interesting tests of the Standard Model and its extensions.

26 pages REVTEX + 7 figures. Some typos corrected, figure 5 and 7 modified. This version will appear on Physical Review D