First observation of the decay B0s → K0S K ∗(892)0 at LHCb

Abstract

A search for B0(s) → K0S K ∗(892)0 decays is performed using pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected with the LHCb detector at a centre-of-mass energy of 7 TeV. The B 0s → K0S K ∗(892)0 decay is observed for the first time, with a significance of 7.1 standard deviations. The branching fraction is measured to be

B(B0s→K¯0K∗(892)0)+B(B0s→K0K¯∗(892)0)=(16.4±3.4±2.3)×10−6, where the first uncertainty is statistical and the second is systematic. No evidence is found for the decay B 0 → K 0S K ∗(892)0 and an upper limit is set on the branching fraction, B(B0→K¯0K∗(892)0)+B(B0→K0K¯∗(892)0)<0.96×10−6 , at 90 % confidence level. All results are consistent with Standard Model predictions.