Publicação
Uniformity of the energy response of the ATLAS hadronic Tile calorimeter to cosmic muons
| Resumo: | TileCal is the ATLAS barrel hadronic calorimeter. It’s a sampling calorimeter of scintillating tiles in a steel matrix with the goal of measuring the position and energy of particle jets with an optimized performance. It went through several tests since its installation in the ATLAS cavern, particularly involving the commissioning of the calorimeter with cosmic ray muons. I used the TileMuonFitter algorithm that reconstructs the muon track using only the cells from TileCal and calculating the crossed path length, it gives the average energy loss of the muon for each detector layer. Detailed studies were carried out to establish the selection cuts and to determine the systematic uncertainties associated to each of them. Two different datasets were used: ID-COMM, that requires a track in the Inner Detector; and RPC that didn’t require this constraint. The results obtained were 5 % higher than in previous studies but, with a energy loss agreement with the simulations within of 3 % , it was able to confirm, although with larger uncertainties, the good setting of the EM scale for layers A and BC. Also in agreement with previous results, there was an indication of a possible layer miscalibration since layer D, for the Long Barrel presented a higher energy loss value. The repeatability and the reproducibility of the TMF method were both tested by comparing the results for different runs and in the two datasets: for LB both values were within 1 %. For EB the results were less conclusive, within 2.5 % and 5-10 % respectively. A uniformity of the energy response variation over Ø of ± 2 %, using ID-COMM, was obtained for layer A in LB for 36 of the 49 modules present in the study. A full coverage was obtained, using RPC, for layer A in LB with a uniformity of ± 5 %. Also using RPC, 78,4 % of the 384 TileCal modules were present in the study and only 6 didn’t comply with the detector requirements (10 %). |
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| Autores principais: | Sousa, Mário José da Cunha Sargedas de |
| Assunto: | Engenharia física Teses de mestrado - 2010 |
| Ano: | 2010 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | TileCal is the ATLAS barrel hadronic calorimeter. It’s a sampling calorimeter of scintillating tiles in a steel matrix with the goal of measuring the position and energy of particle jets with an optimized performance. It went through several tests since its installation in the ATLAS cavern, particularly involving the commissioning of the calorimeter with cosmic ray muons. I used the TileMuonFitter algorithm that reconstructs the muon track using only the cells from TileCal and calculating the crossed path length, it gives the average energy loss of the muon for each detector layer. Detailed studies were carried out to establish the selection cuts and to determine the systematic uncertainties associated to each of them. Two different datasets were used: ID-COMM, that requires a track in the Inner Detector; and RPC that didn’t require this constraint. The results obtained were 5 % higher than in previous studies but, with a energy loss agreement with the simulations within of 3 % , it was able to confirm, although with larger uncertainties, the good setting of the EM scale for layers A and BC. Also in agreement with previous results, there was an indication of a possible layer miscalibration since layer D, for the Long Barrel presented a higher energy loss value. The repeatability and the reproducibility of the TMF method were both tested by comparing the results for different runs and in the two datasets: for LB both values were within 1 %. For EB the results were less conclusive, within 2.5 % and 5-10 % respectively. A uniformity of the energy response variation over Ø of ± 2 %, using ID-COMM, was obtained for layer A in LB for 36 of the 49 modules present in the study. A full coverage was obtained, using RPC, for layer A in LB with a uniformity of ± 5 %. Also using RPC, 78,4 % of the 384 TileCal modules were present in the study and only 6 didn’t comply with the detector requirements (10 %). |
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