| Experiment | Measurement | Reference |
|---|---|---|
| Belle | \([3.0 ^{+1.5}_{-0.8}\mbox{ (stat)} ^{+3.7}_{-1.6}\mbox{ (syst)}] \times 10^{-5}\) | PRD 78:072004,2008 |
| BaBar | < \(1.8 \times 10^{-5}\) | PRD 85, 052003 (2012) |
| Average | \(\mathbf{[3.0 ^{+4.0}_{-1.8}\mbox{ (combined)}] \times 10^{-5}}\) |