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.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-329747 |
| Date | January 2017 |
| Creators | Thorén, Viktor |
| Publisher | Uppsala universitet, Kärnfysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | FYSAST ; FYSMAS1061 |
Page generated in 0.0021 seconds