Measurement of the Differential $q^2$ Spectrum and Forward-Backward Asymmetry for $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$

Abstract

We report measurements of the differential $q^2$ spectrum and the forward-backward asymmetry for $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$, where $\ell$ represents an electron or a muon, with a data sample of 253 fb${}^{-1}$ accumulated on the $\hat{I}\yen (4S)$ resonance with the Belle detector at KEKB. We also present measurements of the branching fractions and their ratios.

BELLE-CONF-0415, submitted to FPCP04, Daegu, Korea and ICHEP04, Beijing, China