Precision measurement of the $\Xi^0$ mass and the branching ratios of the decays $\Xi^0\rightarrow\Lambda\gamma$ and $\Xi^0\rightarrow\Sigma^0\gamma$

A new precision measurement of the \(\Xi^0\) mass has been performed at the NA48 experiment at the CERN SPS. The value obtained is [1314.82\(\pm\)0.06 (stat.) \(\pm\)0.2 (syst.)]\,\mbox{MeV/c}\(^2\). The branching ratios of \(\Xi^0\) radiative decays have been measured as: Br\((\Xi^0\rightarrow\Lambda\gamma)=[1.90\pm0.34 (stat.) \pm0.19 (syst.)] \cdot 10^{-3}\) and Br\((\Xi^0\rightarrow\Sigma^0\gamma)=[3.14\pm0.76 (stat.)\pm0.32 (syst.)]\cdot 10^{-3}\).