Kavli Affiliate: T. Higuchi

| Authors: Belle II Collaboration: F. Abudinén, I. Adachi, K. Adamczyk, L. Aggarwal

| Summary:

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 containing $198 times 10^{6}$ $Boverline{B}$ pairs. We

measure a branching fraction $mathcal{B}(B^0 rightarrow pi^0 pi^0) = (1.38

pm 0.27 pm 0.22) times 10^{-6}$ and a $it CP$ asymmetry $mathcal{A}_{rm

CP}(B^0 rightarrow pi^0 pi^0) = 0.14 pm 0.46 pm 0.07$, where the first

uncertainty is statistical and the second is systematic.