First observation of the decay B(s)^0 → K(S)^0K∗(892)^0 at LHCb

First observation of the decay Bs0 → KS0K∗(892)0 at LHCb A search for B(s)0 → KS0K∗(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 Bs0 → KS0K∗(892)0 decay is observed for the first time, with a significance of 7.1 standard deviations. The branching fraction is measured to be (Bs0 → K̅0K∗(892)0) + (Bs0 → K0K̅∗(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 B0 → KS0K∗(892)0 and an upper limit is set on the branching fraction, (B0 → K̅0K∗(892)0) + (B0 → K0K̅∗(892)0) < 0.96 × 10−6, at 90 % confidence level. All results are consistent with Standard Model predictions.