| Experiment | Measurement | Reference |
|---|---|---|
| Belle | \([4.1 \pm 0.6\mbox{ (stat)} \pm 0.9\mbox{ (syst)}] \times 10^{-4}\) | PLB 634, 155 (2006) ( |
| BaBar | \([2.6 \pm 0.5\mbox{ (stat)} \pm 0.4\mbox{ (syst)}] \times 10^{-4}\) | PRL 102 132001 (2009) |
| Average | \(\mathbf{[3.0 \pm 0.6\mbox{ (combined)}] \times 10^{-4}}\) |