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Alignment of the ATLAS Inner Detector upgraded for the LHC Run II

ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, notably quality of its offline alignment....

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Autor principal: Jimenez Pena, Javier
Lenguaje:eng
Publicado: 2015
Materias:
Acceso en línea:http://cds.cern.ch/record/2008726
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author Jimenez Pena, Javier
author_facet Jimenez Pena, Javier
author_sort Jimenez Pena, Javier
collection CERN
description ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, notably quality of its offline alignment. ATLAS is equipped with a tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). Offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters. The task requires using very large data sets and represents a considerable numerical challenge in terms of both CPU time and precision. The adopted strategy uses a hierarchical approach to alignment, combining local and global least squares techniques. An outline of the track based alignment approach and its implementation within the ATLAS software will be presented. Special attention will be paid to integration to the alignment framework of the IBL, which plays the key role in precise reconstruction of the collider luminous region, interaction vertices and identification of long-lived heavy flavor states. Techniques allowing to pinpoint and eliminate tracking systematics due to alignment as well as strategies to deal with time-dependent variations will be briefly covered. Performance from Cosmic Ray commissioning run and status from proton-proton collision in LHC Run II will be discussed.
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spelling cern-20087262019-09-30T06:29:59Zhttp://cds.cern.ch/record/2008726engJimenez Pena, JavierAlignment of the ATLAS Inner Detector upgraded for the LHC Run IIParticle Physics - ExperimentATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, notably quality of its offline alignment. ATLAS is equipped with a tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). Offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters. The task requires using very large data sets and represents a considerable numerical challenge in terms of both CPU time and precision. The adopted strategy uses a hierarchical approach to alignment, combining local and global least squares techniques. An outline of the track based alignment approach and its implementation within the ATLAS software will be presented. Special attention will be paid to integration to the alignment framework of the IBL, which plays the key role in precise reconstruction of the collider luminous region, interaction vertices and identification of long-lived heavy flavor states. Techniques allowing to pinpoint and eliminate tracking systematics due to alignment as well as strategies to deal with time-dependent variations will be briefly covered. Performance from Cosmic Ray commissioning run and status from proton-proton collision in LHC Run II will be discussed.ATL-SOFT-SLIDE-2015-180oai:cds.cern.ch:20087262015-04-14
spellingShingle Particle Physics - Experiment
Jimenez Pena, Javier
Alignment of the ATLAS Inner Detector upgraded for the LHC Run II
title Alignment of the ATLAS Inner Detector upgraded for the LHC Run II
title_full Alignment of the ATLAS Inner Detector upgraded for the LHC Run II
title_fullStr Alignment of the ATLAS Inner Detector upgraded for the LHC Run II
title_full_unstemmed Alignment of the ATLAS Inner Detector upgraded for the LHC Run II
title_short Alignment of the ATLAS Inner Detector upgraded for the LHC Run II
title_sort alignment of the atlas inner detector upgraded for the lhc run ii
topic Particle Physics - Experiment
url http://cds.cern.ch/record/2008726
work_keys_str_mv AT jimenezpenajavier alignmentoftheatlasinnerdetectorupgradedforthelhcrunii