000004234 001__ 4234
000004234 005__ 20240408131539.0
000004234 037__ $$aBELLE2-MTHESIS-2024-009
000004234 041__ $$aeng
000004234 100__ $$aShu-Ping Lin
000004234 245__ $$aTime-Integrated Measurement of the Branching Fraction and Direct CP Asymmetry of B0 → KS0π0 Decay at Belle II
000004234 260__ $$aTaipei$$bNational Taiwan University$$c2023
000004234 300__ $$amult. p
000004234 500__ $$aPresented on 27 03 2023
000004234 502__ $$aMSc$$bTaipei, National Taiwan University$$c2023
000004234 520__ $$aWe report updated measurements of the branching ratio and the direct CP-violating asym- metry in B0 → KS0π0 decay at Belle II. The flavour information of the decay is obtained from the pair-produced neutral B partner Btag, and the direct CP asymmetry parame- ter is determined with the time-integrated method. We analyse the 2019-2022 Belle II data from e+e− collisions produced by the asymmetric-energy SuperKEKB collider at the Υ(4S) resonance. The data analysed contain 387 million BB pairs and correspond to an integrated luminosity of 362 fb−1. We obtain the branching fraction and the direct CP asymmetry B(B0 → K0π0) = (10.16 ± 0.65 ± 0.65) × 10−6, A(B0 → K0π0) = −0.06 ± 0.15 ± 0.05, where the first uncertainties are statistical and the second systematic. With other Belle II B → Kπ measurements of branching fractions and direct CP asymmetries, we compute the Kπ isospin sum rule to be IKπ = −0.03 ± 0.13 ± 0.05, which is in agreement with the standard model prediction of zero.
000004234 700__ $$aPao-Ti Chang$$edir.
000004234 8560_ $$flin@pd.infn.it
000004234 8564_ $$uhttps://docs.belle2.org/record/4234/files/BELLE2-MTHESIS-2024-009.pdf
000004234 980__ $$aTHESIS