| Experiment | Measurement | Reference |
|---|---|---|
| Belle | \([6.7 \pm 1.1\mbox{ (stat+syst combined)}] \times 10^{-4}\) | PRD 67, 032003(2003) |
| BaBar | \([6.46 \pm 0.65\mbox{ (stat)} \pm 0.44\mbox{ (syst)} \pm 0.25\mbox{ (psi(2S) br (correlated))}] \times 10^{-4}\) | PRL 94 141801 (2005) |
| Average | \(\mathbf{[6.55 \pm 0.66\mbox{ (combined)}] \times 10^{-4}}\) |