Experiment	Measurement	Reference
Belle	< \(7.4 \times 10^{-6}\)	PRD 85 (2012) 091102
BaBar	< \(6.3 \times 10^{-5}\)	PRL 91 071801 (2003)
Average	< \(\mathbf{7.4 \times 10^{-6}}\)