Measurement of Branching Fractions and Polarization in $B\ensuremath{\rightarrow}\ensuremath{\varphi}{K}^{(*)}$ Decays

Measurement of Branching Fractions and Polarization in $B \to φ K^{(*)}$ Decays

K.-F. Chen et al. (Belle Collaboration)

Phys. Rev. Lett. 91, 201801 – Published 10 November 2003

Abstract

We present the first measurement of decay amplitudes in $B \to φ K^{*}$ and measurements of branching fractions in $B \to φ K^{(*)}$ decays based on $78.1 {f b}^{- 1}$ of data recorded at the $Υ (4 S)$ resonance with the Belle detector at the KEKB $e^{+} e^{-}$ storage ring. The decay amplitudes for the different $φ K^{* 0}$ helicity states are measured from the angular distributions of final state particles in the transversity basis. The longitudinal and transverse complex amplitudes are $| A_{0} |^{2} = 0.43 \pm 0.09 \pm 0.04$ , $| A_{⊥} |^{2} = 0.41 \pm 0.10 \pm 0.04$ , $\arg (A_{∥}) = - 2.57 \pm 0.39 \pm 0.09$ , and $\arg (A_{⊥}) = 0.48 \pm 0.32 \pm 0.06$ . The direct $C P$ -violating asymmetries are found to be consistent with zero.