Observation of the B0s→η′η′ Decay

Abstract

The first observation of the B0s→η′η′ decay is reported. The study is based on a sample of proton-proton collisions corresponding to 3.0 fb−1 of integrated luminosity collected with the LHCb detector. The significance of the signal is 6.4 standard deviations. The branching fraction is measured to be [3.31±0.64(stat)±0.28(syst)±0.12(norm)]×10−5, where the third uncertainty comes from the B±→η′K± branching fraction that is used as a normalization. In addition, the charge asymmetries of B±→η′K± and B±→ϕK±, which are control channels, are measured to be (−0.2±1.3)% and (+1.7±1.3)%, respectively. All results are consistent with theoretical expectations.