Experiment	Measurement	Reference
LHCb	\([2.1 \pm 0.5\mbox{ (stat)} ^{+0.3}_{-0.5}\mbox{ (syst)}] \times 10^{-2}\)	PRD 84 092001 (2011), Erratum: PRD 85 039904 (2012)
Average	\(\mathbf{[2.1 ^{+0.6}_{-0.7}\mbox{ (combined)}] \times 10^{-2}}\)