Study of Discrete Symmetries in η' Meson Decays with BESIII

Abstract: This thesis studies the rare decay η' → π+π-e+e- using Monte Carlo simulations and data from the BES-III detector in Beijing, China. The branching ratio of the reaction was measured at BES-III in 2013 using a data set of 225×106 J/Ψ events. This work lays the groundwork for an updated branching ratio measurement using the full data set of 1.3×109 J/Ψ and determines a potential CP-violating asymmetry in the angle between the decay planes of the π+π-- and e+e--pairs. A total of 2558 signal events are observed after cuts, and the asymmetry parameter is determined to be  Aφ = (1.96 ± 1.97stat.± 0.4syst. ) × 10-2. The result is consistent with zero within the uncertainty.