| Experiment | Measurement | Reference |
|---|---|---|
| BaBar | \([1 ^{+1}_{-1}\mbox{ (stat)} ^{+0}_{-0}\mbox{ (syst)}] \times 10^{0}\) | PRD(RC) 82 011101 (2010) |
| BaBar | \([0.41 \pm 0.24\mbox{ (stat)} \pm 0.05\mbox{ (syst)}] \times 10^{0}\) | PRD(RC) 77 111101 (2008) |
| Average | \(\mathbf{[0.47 \pm 0.23\mbox{ (combined)}] \times 10^{0}}\) |