The local hadronic calibration scheme developed for the reconstruction and calibration of jets and missing transverse energy in ATLAS has been evaluated using data obtained during combined beam tests ...of modules of the ATLAS liquid argon endcap and forward calorimeters. These tests covered the pseudorapidity range of 2.5 < | ? | < 4.0 . The analysis has been performed using special sets of calibration weights and corrections obtained with the Geant4 simulation of a detailed beam-test setup. The evaluation itself has been performed through the careful study of specific calorimeter performance parameters such as e.g. energy response and resolution, shower shapes, as well as different physics lists of the Geant4 simulation.
The local hadronic calibration scheme developed for the reconstruction and calibration of jets and missing transverse energy in ATLAS has been evaluated using data obtained during combined beam tests ...of modules of the ATLAS liquid argon endcap and forward calorimeters. These tests covered the pseudorapidity range of 2.5<|η|<4.0. The analysis has been performed using special sets of calibration weights and corrections obtained with the Geant4 simulation of a detailed beam-test setup. The evaluation itself has been performed through the careful study of specific calorimeter performance parameters such as e.g. energy response and resolution, shower shapes, as well as different physics lists of the Geant4 simulation.
The pseudorapidity region
2.5
<
|
η
|
<
4.0
in ATLAS is a particularly complex transition zone between the endcap and forward calorimeters. A set-up consisting of
1
4
resp.
1
8
of the full azimuthal ...acceptance of the ATLAS liquid argon endcap and forward calorimeters has been exposed to beams of electrons, pions and muons in the energy range
E
⩽
200
GeV
at the CERN SPS. Data have been taken in the endcap and forward calorimeter regions as well as in the transition region. This beam test set-up corresponds very closely to the geometry and support structures in ATLAS. A detailed study of the performance in the endcap and forward calorimeter regions is described. The data are compared with MC simulations based on GEANT 4 models.
Using a Monte Carlo code based on the GEANT package the energy resolution of a scintillating fibre calorimeter was investigated as a function of the volume ratio of passive (absorber) to active ...(fibres) material, fibre radius, light reflection coefficient at fibre end, fibre transparency, and incident particle tilt angle. The obtained MC results were confronted with the existing experimental data. Good agreement between the simulation and experiment was found in most cases. A simple formula describing the stochastic term of the energy resolution as a function of the calorimeter basic parameters has been found.
This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) ...in the framework of the non-parametrical method. The non-parametrical method utilizes only the known
e/
h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within ±1% of the true values and the fractional energy resolution is
(58±3)%/
E
+(2.5±0.3)%⊕(1.7±0.2)/E
. The value of the
e/
h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74±0.04 and agrees with the prediction that
e/
h>1.66 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to
300
GeV
.
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