Performance study of the separation of the full hadronic WW and ZZ events at the CEPC

The separation of the full hadronic WW and ZZ events is an important benchmark for the CEPC detector design and performance evaluation. This separation performance is determined by the intrinsic boson mass distributions, the detector performance, and the jet confusion. The latter refers to the uncertainties induced by the jet clustering and pairing algorithms. Using the CEPC baseline simulation, we demonstrate that the full hadronic WW and ZZ events can be efficiently separated. We develop an analytic method that quantifies the impact of each component and conclude that the jet confusion dominates the separation performance. The impacts of the initial state radiations and the heavy flavor jets are also analyzed and confirmed to be critical for the separation performance.