| Experiment | Measurement | Reference |
|---|---|---|
| CDF | \([9.0 \pm 2.2\mbox{ (stat)} \pm 0.9\mbox{ (syst)}] \times 10^{-4}\) | PRD 58 072001 (1998) |
| BaBar | \([6.49 \pm 0.59\mbox{ (stat)} \pm 0.94\mbox{ (syst)} \pm 0.25\mbox{ (psi(2S) br (correlated))}] \times 10^{-4}\) | PRL 94 141801 (2005) |
| Average | \(\mathbf{[6.96 \pm 1.03\mbox{ (combined)}] \times 10^{-4}}\) | CL=0.3408 |