Analysis of the decay J/ψ → ωπ⁺π^- in BESIII and developments for the cooling system and the thermal isolation of the PANDA-EMC

The present thesis consists of two independent parts. One part contains the analysis of the decay channel Jψ → ωπ⁺π^- with data of the BESIII experiment. The other part deals with developments of cooling systems and a thermal isolation for the forward end-cap of the electromagnetic calorimeter of the target spectrometer of the PANDA experiment. Part 1 contains the analysis of the decay Jψ → ωπ⁺π^- to the final state π⁺π^-π⁰π⁺π^-. Basing on 8.6 millions measured Jψ by the DM2 experiment the branching ratios of decays to the final state π⁺π^-π⁰π⁺π^- were determined. The branching ratio for the channel Jψ → ωπ⁺π^- was measured to (7.0 ± 1.6) . 10^-3, basing on 18058 events. Also the combined branching ratio B(Jψ → ωf₂(1270),f₂(1270) → π⁺π^-) was determined to (2.6 ± 0.5) . 10^-3, hereby 5730 f₂(1270) events were reconstructed. Beside the determination of branching ratios in the framework of the BESII experiment a partial-wave analysis of the decay Jψ → ωπ⁺π^- to the final state π⁺π^-π⁰π⁺π^- was performed. The used data set had a quantity of 58 millions measured events. Following resonances could be identified and fitted to the reconstructed data: σ, f₀(980), f₂(1270), f₂(1565), and f₂(2240) with the decay to π⁺π^- as well as b₁(1235) and ρ(1450) with the decays to ωπ^±. Part II deals with developments for the PANDA experiment. An important component of the PANDA experiment is the electromagnetic calorimeter of the target spectrometer, which serves for the energy measurement of the light particles, produced in anti pp annihilations and subsequent decays, like electrons, positrons, and photons.