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000001904 037__ $$aBELLE2-CONF-PH-2020-001 000001904 041__$$aeng
000001904 100__ $$aF. Abudinen 000001904 245__$$aCharmless B decay reconstruction in 2019 data
000001904 260__ $$a$$c2020-04-10
000001904 300__ $$a10 000001904 520__$$aWe 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 $B^0 \to K^+\pi^-$, $B^0 \to \pi^+\pi^-$, $B^+ \to K^0_S(\to \pi^+\pi^-)\pi^+$, $B^+ \to K^+\pi^0(\to \gamma\gamma)$, $B^+ \to K^+K^-K^+$,  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.
000001904 6531_ $$aCharmless 000001904 6531_$$aRediscovery
000001904 6531_ $$aHadronic B 000001904 700__$$aE. Ganiev
000001904 700__ $$aR. Manfredi 000001904 700__$$aS. Raiz
000001904 700__ $$aD. Tonelli 000001904 8560_$$fdiego.tonelli@desy.de
000001904 8564_ $$uhttps://docs.belle2.org/record/1904/files/BELLE2-CONF-PH-2020-001.pdf 000001904 8564_$$uhttps://docs.belle2.org/record/1904/files/PublicCharmlessForMoriond.pdfzFinal