Fig. 19.

Muon reconstruction efficiency as a function of $\mathit{\eta }$ measured in $Z\to \mathit{\mu }\mathit{\mu }$ events in the 2011 data sample for different muon reconstruction types. CaloTag muons are only shown in the region $|\mathit{\eta }|<0.1$, where they are used in physics analyses. For the efficiency, the error bars indicate the statistical uncertainty. The panel at the bottom shows the ratio between the measured and MC efficiencies. The error bars on the ratios show the combination of statistical and systematic uncertainties. The lower efficiency of CB muons at $|\mathit{\eta }|\approx 1.2$ is due to the fact that some of the MS chambers were not yet installed