000002335 001__ 2335
000002335 005__ 20210524113325.0
000002335 037__ $$aBELLE2-CONF-PH-2021-007
000002335 041__ $$aeng
000002335 100__ $$aBelle II Collaboration
000002335 245__ $$aMeasurement of the branching fractions of B → η'K decays using 2019/2020 Belle II data
000002335 260__ $$a$$c2021-04-13
000002335 300__ $$a17
000002335 520__ $$aThis note describes the rediscovery of B → η' K decays in Belle II data, both in the charged and neutral final state: B0 → η' KS and B± → η' K± . The η' is searched for in two decay modes: η' → ηπ+ π− with η → γγ, and η' → ργ. The analysis uses data collected in 2019 and 2020 at the SuperKEKB asymmetric e+ e− collider, with an integrated luminosity of 62.8 fb−1 , corresponding to 68.2 million of BB pairs produced. The signal yield is obtained via an unbinned maximum likelihood fit to signal sensitive variables, obtaining branching ratios: BR( B± → η' K±) = 63.4 (+3.4/−3.3) (stat) ± 3.2 (syst) × 10-6 BR( B0 → η' K ) = 59.9 (+5.8/-5.5) (stat) ± 2.9 (syst) × 10-6 which are consistent with world average.
000002335 6531_ $$ab->qqs
000002335 6531_ $$acharmless b decay
000002335 6531_ $$aTDCPV
000002335 8560_ $$fstefano.lacaprara@pd.infn.it
000002335 8564_ $$uhttps://docs.belle2.org/record/2335/files/belle2-conf-ph-2021-007.pdf