| Experiment | Measurement | Reference |
|---|---|---|
| Belle | \([1.09 \pm 0.08\mbox{ (stat)} \pm 0.16\mbox{ (syst)}] \times 10^{-3}\) | Experiment Note |
| Belle | \([6.2 \pm 1.2\mbox{ (stat)} \pm 1.8\mbox{ (syst)}] \times 10^{-4}\) | PLB 553, 159 (2003) |
| Average | \(\mathbf{[9.0 \pm 1.4\mbox{ (combined)}] \times 10^{-4}}\) |