Study of the response to isolated muons from collisions of the ATLAS Tile Calorimeter’s gap/crack cells

This thesis presents a calibration study of the ATLAS Tile Calorimeter’s gap/crack cells, using isolated muons from pp collisions at a center of mass energy of √s = 7 TeV and an integrated luminosity of 1 fb^−1. Muons, as minimum ionising particles, deposit a well-described amount of energy in the calorimeter. Therefore, they can be used to study the agreement between the measured and expected response. The W → µν events are selected using high level triggering, after which pion decay remains the main background. Dedicated studies on the TileCal calibration systems have shown that the response of the channels is time-dependent and therefore needs to be monitored. A method is proposed to determine detector modules that are miscalibrated, allowing no more than 3σ deviation from the Monte Carlo predictions. The so-called TileCal Unified Calibration Software has been improved to monitor the calibration status of the detector over time, incorporating the different calibration systems. Miscalibrations should be corrected for.