| Experiment | Measurement [10-2] | $\Delta\chi^2$ | Reference | Comments |
|---|---|---|---|---|
| Average | $3.2 \pm3.4$ | 0.22 | $p=0.64$ (ndf=1) | |
| Belle | $2.2 \pm3.9 \pm0.9$ | 0.06 | Phys.Rev.Lett. 114,151601 (2015) | $E^{*}_{\gamma} \geq 2.1~\text{GeV}$ where $E^{*}_{\gamma}$ is the photon energy in the center-of-mass frame. |
| BaBar | $5.7 \pm6.0 \pm1.8$ | 0.16 | Phys.Rev.Lett. 109,191801 (2012) | $2.1 < E^{*}_{\gamma} < 2.8~\text{GeV}$ where $E^{*}_{\gamma}$ is the photon energy in the center-of-mass frame. |