2020/09/20 by Belle II Collaboration, Abudinén, F., Adachi, I. +544
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2009.09452
We report on first measurements of branching fractions~(B) and CP-violating charge asymmetries~(A) in charmless B decays at Belle~II. We use a sample of electron-positron collisions collected in 2019 and 2020 at the Υ(4S) resonance and corresponding to 34.6 fb-1 of integrated luminosity. We use simulation to determine optimized event selections. The ΔE distributions of the resulting samples, restricted in M\rm bc, are fit to determine signal yields. Signal yields are corrected for efficiencies determined from simulation and control data samples to obtain branching fractions and CP-violating asymmetries for flavour-specific channels. These are the first measurements in charmless decays reported by Belle~II. Results are compatible with known determinations and show detector performance comparable with the best Belle results offering a reliable basis to assess projections for future reach.