Observation of the decay B0 →η′K∗ (892)0

Abstract

We report a search for charmless hadronic decays of neutral B mesons to η′K∗(892)0. The results are based on a 711fb-1 data sample that contains 772×106BB¯ pairs, collected at the (4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. We observe the decay for the first time with a significance of 5.0 standard deviations and obtain its branching fraction B[B0→η′K∗(892)0]=[2.6±0.7(stat)±0.2(syst)]×10-6. We also measure the CP-violating asymmetry as ACP[B0→η′K∗(892)0]=-0.22±0.29(stat)±0.07(syst).