Muon Isolation Efficiency Studies in the $Z^{0} \to\mu\mu$ channel at the ATLAS-Detector

The investigation of the Z0 bosons + jets production at hadron colliders can be a powerful probe to existing quantum chromodynamic calculation models as well as electroweak prediction and precision measurements. Furthermore, the Z0 → µµ + jets decay channel contributes as a major background to supersymmetric Higgs modells. Therefore, a powerful method to select Z0 → µµ + jets events is essential. This selection can be based on the usage of isolation criteria to select the final state muons. This thesis describes a method to extract the efficiencies of different isolation criteria from measured or simulated experimental data of the ATLAS experiment at the LHC. Hereby, Z0 → µµ + jets events are selected from data first to apply isolation criteria on the final state muons and calculate the efficiency of the criteria.