Measurement of the Decay Ξ^{0}\toΛγ with Entangled Ξ^{0}\barΞ^{0} Pairs

In this Letter, a systematic study of the weak radiative hyperon decay \Xi^{0}\to\Lambda\gamma at an electron-positron collider using entangled \Xi^{0}\bar{\Xi}^{0} pair events is presented. The absolute branching fraction for this decay has been measured for the first time, and is \left(1.347 \pm 0.066_{\mathrm stat.}\pm0.054_{\mathrm syst.}\right)\times 10^{-3}. The decay asymmetry parameter,... Show more