Measurement of the branching fraction of the $B^0 \to K_S^0 \pi^0 \gamma$ decay using 190 fb$^{-1}$ of Belle II data

TL;DR

This paper reports the measurement of the branching fraction of the decay $B^0 o K_S^0 \pi^0 \gamma$ using 190 fb$^{-1}$ of data from the Belle II experiment, confirming previous results with improved data.

Contribution

First measurement of the $B^0 o K_S^0 \pi^0 \\gamma$ decay branching fraction using Belle II data at 190 fb$^{-1}$, providing a more precise value consistent with prior measurements.

Findings

Measured branching fraction: (7.3 ± 1.8 (stat) ± 1.0 (syst)) × 10^{-6}

Signal yield: 121 ± 29 events

Results agree with previous measurements.

Abstract

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.