Thibaud Humair ; Hans-Günther Moser ; Justin Skorupa

19 September 2022

Abstract: We determine the branching fractions B and CP asymmetries ACP of the decays B+ → π+π0 and B+ → K+π0. The results are based on a data set containing 198 million bottom-antibottom meson pairs corresponding to an integrated luminosity of 190 fb−1 recorded by the Belle II detector in energy-asymmetric electron-positron collisions at the Υ (4S) resonance. We measure B(B+ → π+π0) = (6.12 ± 0.53 ± 0.53) × 10−6, B(B+ → K+π0) = (14.30 ± 0.69 ± 0.79) × 10−6, ACP (B+ → π+π0) = −0.085 ± 0.085 ± 0.019, ACP (B+ → K+π0) = 0.014 ± 0.047 ± 0.010, where the first uncertainties are statistical and the second are systematic. These results improve a previous Belle II measurement and agree with the world averages.