Simulation and validation of the ATLAS Tile Calorimeter response

S N Karpov

doi:10.1088/1748-0221/9/09/c09018

Abstract

The Tile Calorimeter is the central section of the ATLAS hadronic calorimeter at the Large Hadron Collider. Scintillation light produced in the tiles is transmitted by wavelength shifting fibers to photomultiplier tubes (PMTs). The resulting electronic signals from approximately 10000 PMTs are amplified, shaped and digitized before being transferred to off-detector data acquisition systems. This paper describes the detailed simulation of this large scale calorimeter from the implementation of the geometrical elements down to the realistic description of the electronics readout pulses, the special noise treatment and the signal reconstruction. Recently improved description of the optical and electronic signal propagation is highlighted and the validation with the real particle data is presented.

Highlights

Geant4 hit before adding this hit energy to the total energy
The calibration hits give us very useful information for the energy calibration studies: calibration of each ATLAS sub-detector and verification of its geometry; understanding of the full energy balance of specific event types, for example evaluation of "missing visible energy" which can be caused by energy deposits in dead materials, by leakage, or by energy flow at |η| > 5.9; identification of the full energy which is associated with each jet in multi-jet events
The of muons from the W→μν events for the collision data (Figure 1, red) agrees very well with simulation with U-shape included (Figure 2, right, red). 2.3 Sampling fraction calculation The sampling fraction (SF) is the conversion factor between the energy released in the scintillators and the total energy deposited in the TileCal cells

Summary

Tile Calorimeter simulations with calibration hits

Calibration hits allow us to record the energy deposited in the scintillator, and in the non-sensitive parts of TileCal. The calibration hits give us very useful information for the energy calibration studies: calibration of each ATLAS sub-detector and verification of its geometry; understanding of the full energy balance of specific event types, for example evaluation of "missing visible energy" which can be caused by energy deposits in dead materials, by leakage, or by energy flow at |η| > 5.9; identification of the full energy which is associated with each jet in multi-jet events. It is possible to simulate the TileCal standalone Test Beams (3 barrel modules or 2 barrels and 2 extended barrels) as well as the Combined Test Beam of 2004 [5]. This is useful for the sampling fraction calculation

Cell response as function of the particle impact point

Validation of EM scale with muons in ATLAS

Findings

Conclusion