A study to optimize the simulation of the TileCal response using collision muons

The ATLAS experiment at the CERN Large Hadron Collider (LHC) is designed to fully exploit the exciting opportunities for fundamental discoveries at high-energy frontier. The proton-proton center of mass energy of 14 TeV, the design luminosity of $10^{34}cm^{−2}s^{−1}$ and the time between bunch crossings of 25 ns are the basic collider parameters that drove the design of the experiment. One component of the ATLAS calorimeter system is Tile Calorimeter (TileCal). It is a sampling plastic scintillator/iron detector. A Sr scan of one of the TileCal scintillator tile shows that mesured signal in the center of tile is different from the signal in the edges. The shape of the distribution of tile response vs. $\Delta{\phi}$ is so-called U-shape. $\Delta{\phi}$ is the difference between the azimuth angle of the track and the azimuth position of the center of the tile. In the Monte Carlo (MC) simulation of the TileCal response this U-shape is not yet included. In this work the U-shape was implemented in the MC simulation and checked U-shape modelization. Results shows that agreement between data and MC has improved after U-shape implementation, but agreement data/MC is bad in the edges of tiles (large value of |$\Delta{\phi}$|). In order to optimize the simulation of the TileCal response it is needed to continue study of U-shape of data and improve U-shape implementation in MC simulation.