000002517 001__ 2517
000002517 005__ 20210701011454.0
000002517 037__ $$aBELLE2-PTHESIS-2021-013
000002517 041__ $$aeng
000002517 100__ $$aWan Kun
000002517 245__ $$aTime Dependent Charge-Parity Violation in B0 → KS0KS0KS0 in Belle II early operation
000002517 260__ $$aTokyo$$bUniversity of Tokyo$$c2021
000002517 300__ $$amult. p
000002517 500__ $$aPresented on 13 04 2021
000002517 502__ $$aPhD$$bTokyo, University of Tokyo$$c2021
000002517 520__ $$aThe Belle II experiment is a next-generation super B-factory experiment. The tar- geted instantaneous luminosity is 8 × 1035 cm−2s−1 and the expected integrated lumi- nosity is 50 ab−1 by 2030 with the majority of data collected at the Υ(4S) resonance using SuperKEKB accelerator. The thesis is based on the time-dependent CP violation study of B0 → KS0KS0KS0 decay to precisely measure the CP parameters S and A in penguin-dominated b → s transition, which is sensitive to New Physics effects. Such a precise measurement mainly depends on determination of the distance between two vertices of two neutral B mesons. The blind analysis and fit by a unbinned maximum likelihood method are performed using about 62.8 fb−1 recorded experiment data from Belle II detector 2019 and 2020 (spring and summer) operation. The measurement results: S = −sin(2φ1) = −0.82±0.85 (stat)±0.07 (syst) and A = −0.21±0.28 (stat)±0.06 (syst) are obtained. The result is dominated by the statistical uncertainty and currently consistent with the Standard Model, as well as the previous results in the Belle and BaBar. At the 50 ab−1 future Belle II full luminosity, we estimate the total uncertainty of S to be 0.040 ∼ 0.048 in B0 → KS0KS0KS0. This estimation is a preliminary result based on the limited data at present and conservative assumptions on the reduction of the uncertainties, which is subject to change in future. Overall, such total uncertainty can provide a much better probe for searching the New Physics effects in future.
000002517 700__ $$aHiroaki Aihara$$edir.
000002517 8560_ $$fmasashi@phys.s.u-tokyo.ac.jp
000002517 8564_ $$uhttps://docs.belle2.org/record/2517/files/BELLE2-PTHESIS-2021-013.pdf
000002517 980__ $$aTHESIS