First observation of the decay $B_{s}^{0} \to K_{S}^{0} K^{*}(892)^{0}$

TL;DR

This paper reports the first observation of the decay $B_{s}^{0} o K_{S}^{0} K^{*}(892)^{0}$ using LHCb data, measuring its branching fraction and setting limits on related decays, confirming Standard Model predictions.

Contribution

First observation of the decay $B_{s}^{0} o K_{S}^{0} K^{*}(892)^{0}$ with measured branching fraction and upper limits on similar decays, using 7 TeV LHCb data.

Findings

Decay $B_{s}^{0} o K_{S}^{0} K^{*}(892)^{0}$ observed with 7.1 sigma significance.

Branching fraction measured as (16.4 ± 3.4 ± 2.3) × 10^{-6}.

No evidence for $B^{0} o K_{S}^{0} K^{*}(892)^{0}$; upper limit set.

Abstract

A search for $B_{(s)}^{0} \to K_{S}^{0} K^{*}(892)^{0}$ decays is performed using $pp$ collision data, corresponding to an integrated luminosity of $1.0~\text{fb}^{-1}$, collected with the LHCb detector at a centre-of-mass energy of $7~\text{TeV}$. The $B_{s}^{0} \to K_{S}^{0} K^{*}(892)^{0}$ decay is observed for the first time, with a significance of 7.1 standard deviations. The branching fraction is measured to be \begin{equation*} \mathcal{B}(B_{s}^{0} \to \bar{K}^{0} K^{*}(892)^{0}) + \mathcal{B}(B_{s}^{0} \to K^{0} \bar{K}^{*}(892)^{0}) = (16.4 \pm 3.4 \pm 2.3) \times 10^{-6},\\ \end{equation*} where the first uncertainty is statistical and the second is systematic. No evidence is found for the decay $B^{0} \to K_{S}^{0} K^{*}(892)^{0}$ and an upper limit is set on the branching fraction, $\mathcal{B}(B^{0} \to \bar{K}^{0} K^{*}(892)^{0}) + \mathcal{B}(B^{0} \to K^{0} \bar{K}^{*}(892)^{0}) < 0.96 \ \times 10^{-6}, $ at $90\,\% $ confidence level. All results are consistent with Standard Model predictions.