Angular analysis of B-0 -> phi K* decays and search for CP violation at Belle

Abstract

We report the measurements of branching fractions and CP violation asymmetries in B0→ϕK∗ decays obtained in an angular analysis using the full data sample of 772×106BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We perform a partial wave analysis to distinguish among scalar [B0→ϕ(Kπ)∗0], vector [B0→ϕK∗(892)0] and tensor [B0→ϕK∗2(1430)0] components, and determine the corresponding branching fractions to be B[B0→ϕ(Kπ)∗0]=(4.3±0.4±0.4)×10−6, B[B0→ϕK∗(892)0]=(10.4±0.5±0.6)×10−6 and B[B0→ϕK∗2(1430)0]=(5.5+0.9−0.7±1.0)×10−6. We also measure the longitudinal polarization fraction fL in B0→ϕK∗(892)0 and B0→ϕK∗2(1430)0 decays to be 0.499±0.030±0.018 and 0.918+0.029−0.060±0.012, respectively. The first quoted uncertainties are statistical and the second are systematic. In total, we measure 26 parameters related to branching fractions, polarization and CP violation in the B0→ϕK∗ system. No evidence for CP violation is found.