| Experiment | Measurement | Reference |
|---|---|---|
| CDF | \([0.49 \pm 0.06\mbox{ (stat)} \pm 0.05\mbox{ (syst)} \pm 0.08\mbox{ (norm)}] \times 10^{-2}\) | PRL 108, 201801 (2012) |
| Belle | \([0.58 ^{+0.11}_{-0.09}\mbox{ (stat)} \pm 0.13\mbox{ (syst)}] \times 10^{-2}\) | PRD 87 (2013) 031101 |
| Average | \(\mathbf{[0.52 \pm 0.09\mbox{ (combined)}] \times 10^{-2}}\) |