The book reports a joint analysis between the LHCb and BESIII collaborations on measuring the CKM angle with intricate data analysis techniques and rigorous statistical methods. Based on a proposal of an unbinned BPGGSZ method with Fourier expansion, a novel approach is developed. Applying an optimised weighting function across the Dalitz plot, deduced from the decay amplitude and background level in data, the statistical uncertainty of may effectively be improved compared to the current analyses. The feasibility of the approach is proven by tests with pseudo-data generated according to previous experimental measurements. Applying this approach to the data collected by the LHCb and BESIII experiments to measure the CKM angle , the preliminary result obtained has a significantly lower statistical uncertainty than previous measurements. The new approach developed in the thesis provides an important and extremely valuable addition to test the CKM mechanism.
Introduction.- Research Facilities.- Formalism of the BPGGSZ method.-
Signal Extraction.- Fit of 𝑪𝑷 observables.- Systematic
uncertainties .- Results.- Summary and Prospects.
Shunan Zhang is currently a postdoctoral research assistant in the Department of Physics at University of Oxford. He received his B.Eng. from the Department of Engineering Physics at Tsinghua University in 2018 and Ph.D. from the School of Physics at Peking University in 2024. He has been a member of the LHCb collaboration since 2017 and has joined the BESIII collaboration in 2022. His research focuses on CP violation in charged beauty meson decays, as well as strong-phase measurements in associated charm meson decays, which provide critical inputs for CP violation studies.
