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

Abstract

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