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We report on the reconstruction of various charmless $B$ decays from electron-positron collisions at the energy corresponding to the $Upsilon(4S)$ resonance collected with the Belle II detector at the SuperKEKB collider. We use simulation to devise optimized event selections and apply them to the full data set collected in 2019, corresponding to 8.7,fb$^{-1}$ of integrated luminosity. We fit the difference between half of the collision energy and the $B$ candidate energy (in the $Upsilon(4S)$ frame) for events restricted to a signal-rich range in beam-energy-constrained mass to search for charmless signals. Signal yields of approximately 80, 15, 20, 30, 90, and 160 decays are reconstructed for the channels $B^0 to K^+pi^-$, $B^0 to pi^+pi^-$, $B^+ to K^0_S(to pi^+pi^-)pi^+$, $B^+ to K^+pi^0(to gammagamma)$, $B^+ to K^+K^-K^+$, and $B^+ to K^+pi^-pi^+$, respectively. Yields and background contaminations are compatible with those expected from simulation and comparable with those obtained by the Belle experiment. The results show a good understanding of the detector performance and offer a reliable basis to assess projections for future reach.
We report on preliminary measurements of branching fractions, charge-parity-violating asymmetries, and longitudinal polarization fractions in charmless bottom-meson decays from the Belle~II experiment. We use samples of electron-positron collisions c
We report on first measurements of branching fractions~($mathcal{B}$) and CP-violating charge asymmetries~($mathcal{A}$) in charmless $B$ decays at Belle~II. We use a sample of electron-positron collisions collected in 2019 and 2020 at the $Upsilon(4
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8times10^{35}, mathrm{cm}^{-2}mathrm{s}^{-1}$ and
We report on the first calibration of the standard Belle II $B$-flavor tagger using the full data set collected at the $Upsilon(4{rm S})$ resonance in 2019 with the Belle II detector at the SuperKEKB collider, corresponding to 8.7 fb$^{-1}$ of integr
We report the first reconstruction of the $B^{0} to pi^{0} pi^{0}$ decay mode at Belle II using samples of 2019 and 2020 data that correspond to 62.8 fb$^{-1}$ of integrated luminosity. We find $14.0^{+6.8}_{-5.6}$ signal decays, corresponding to a s