Observation of the Decay $B\to K{\ell }^{+}{\ell }^{-}$

K. Abe

We report a search for the flavor-changing neutral current decay $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ using a 29.1 fb${}^{-1}$ data sample accumulated at the ${\rm Y}(4S)$ resonance with th…