We report the measurement of the branching fraction of the $B^0 \to K_S^0 \pi^0 \gamma$ decay in $e^+ e^- \to \Upsilon(4S) \to B \overline{ B}$ data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy collider and corresponding to 190 fb$^{ -1}$ of integrated luminosity. The signal yield is measured to be $121\pm 29\,\hbox{ (stat.)}$, leading to the branching fraction ${ \cal B}\left(B^0 \to K_S^0 \pi^0 \gamma\right) = \left(7.3 \pm 1.8\,\hbox{ (stat.)} \pm 1.0\,\hbox{ (syst.)} \right)\times 10^{ -6}$, which agrees with the known value.
Categories: hep-ex