Study of the Sagitta Resolution of MDT-Chambers

The cosmic ray measurement facility in Garching, Germany, provides a good environment to validate the Geant4 simulation of the MDT-chambers with real data. The sagitta resolution of the muon tracks, reconstructed with the three MDT-chambers of this setup, allows a meaningful test of this comparison. The sagitta resolution of the measurement facility was measured with cosmic muons recorded between 2004 and 2005. This measured resolution was reproduced to a very high accuracy within a detailed Geant4 simulation of the measurement facility and the MDT-chambers. Given this validated simulation, other effects of the sagitta and momentum resolution of the MDT-chambers in the cosmic ray measurement facility, in the ATLAS detector and the H8-testbeam construction are studied. In particular effects of multiple scattering, single tube resolution and alignment are discussed.