| Experiment | Measurement | Reference |
|---|---|---|
| Belle | \([2.4 ^{+1.3}_{-1.4}\mbox{ (stat)} \pm 0.7\mbox{ (syst)}] \times 10^{-6}\) | PRL 107, 091803 (2011) |
| BaBar | \([2.6 \pm 1.8\mbox{ (stat)} \pm 0.2\mbox{ (syst)}] \times 10^{-6}\) | PRL 102 132001 (2009) |
| Average | \(\mathbf{[2.5 \pm 1.2\mbox{ (combined)}] \times 10^{-6}}\) |