Simulation of Cosmic Muons and Comparison with Data from the Cosmic Challenge using Drift Tube Chambers

The reconstruction of cosmic muons is important for the commissioning phase and alignment of the Compact Muon Solenoid experiment (CMS), in particular during the early phases of operation with physics collisions. In this context the Magnet Test/Cosmic Challenge (MTCC) with its comprehensive cosmic data taking periods including the presence of the magnetic field has been like a dress rehearsal of detector hardware and software for the upcoming startup of the CMS detector. In addition to data taking also the comparison with simulated events is a crucial part of physics analyses. This study introduces a new cosmic muon generator, CMSCGEN, and it presents its validation by comparing with data from MTCC. As an example results from a reconstruction study using the barrel Muon System are shown, comparing data and Monte Carlo prediction at the level of single chambers up to reconstructed tracks including momentum measurements.