Improvement on PbWO4 Crystal Intercalibration Precision from Light Yield Measurements at the INFN-ENEA Regional Center
نویسندگان
چکیده
The Electromagnetic Calorimeter of the CMS experiment, consisting of about 75000 Lead Tungstate scintillating crystals, aims at achieving an extreme precision in photon and electron energy measurement. Since the ultimate energy resolution will be affected by the crystal light yield and its uniformity along the crystal axis, systematic measurements of both these parameters are performed in the Regional Centers where the calorimeter modules are assembled. This paper reports on the light yield measurements in Rome Regional Center and investigates the use of these measurements to define an intercalibration procedure for each crystal. For most of the crystals this will represent the only precalibration available at the beginning of the experiment. For this purpose, data obtained in Rome Regional Center have been analyzed in detail to evaluate the currently available precision and to identify ways to improve it. The long term stability of the measurements is investigated as well.
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