| Experiment | Measurement | Reference |
|---|---|---|
| BaBar | < \(0.12 \times 10^{-4}\) | PRL 94 171801 (2005) (superseded) |
| BaBar | \([1.1 \pm 4.3\mbox{ (stat)} \pm 5.5\mbox{ (syst)}] \times 10^{-5}\) | PRL 102 132001 (2009) |
| Average | \(\mathbf{[1.1 \pm 7.0\mbox{ (combined)}] \times 10^{-5}}\) |