| Experiment | Measurement | Reference |
|---|---|---|
| Belle | \([1.8 \pm 0.3\mbox{ (stat)} \pm 0.3\mbox{ (syst)} \pm 0.2\mbox{ (model)}] \times 10^{-4}\) | PRD 69, 112002(2004) |
| BaBar | \([0.18 \pm 0.03\mbox{ (stat)} \pm 0.05\mbox{ (syst)}] \times 10^{-3}\) | Experiment Note |
| Average | \(\mathbf{[1.8 \pm 0.4\mbox{ (combined)}] \times 10^{-4}}\) |