Measurement of the branching fraction and $CP$ asymmetry of $B^0\to {\pi }^0{\pi }^0$ decays using $198\times 10^6$ $B\overline{B}$ pairs in Belle II data

Belle II Collaboration, F. Abudinén, I. Adachi +425

We report measurements of the branching fraction and $CP$ asymmetry in $B^0\to {\pi }^0{\pi }^0$ decays reconstructed at Belle II in an electron-positron collision sample contain…