Abstract
A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of pT> 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of pT= 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in pT, and respectively, 10μm and 30μm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10-12μm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung.
Original language | English |
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Article number | P10009 |
Journal | Journal of Instrumentation |
Volume | 9 |
Issue number | 10 |
DOIs | |
Publication status | Published - 1 Jan 2014 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© CERN 2014 for the benefit of the CMS collaboration.
Funding
Funders | Funder number |
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Not added | ST/H00081X/2 |
Agentschap voor Innovatie door Wetenschap en Technologie | |
Austrian Science Fund | |
Bundesministerium für Bildung und Forschung | |
Chinese Academy of Sciences | |
Consejo Nacional de Ciencia y Tecnología | |
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior | |
Deutsche Forschungsgemeinschaft | |
Estonian Research Council | IUT23-6, IUT23-4 |
European Research Council | |
Fundação para a Ciência e a Tecnologia | |
General Secretariat for Research and Technology | |
Istituto Nazionale di Fisica Nucleare | |
Joint Institute for Nuclear Research | |
Ministry of Education | |
Ministry of Education, Science and Technology | |
Ministry of Science and Technology | |
National Academy of Sciences | |
National Natural Science Foundation of China | |
National Research Foundation | |
National Science Foundation | |
National Science and Technology Development Agency | |
Physicians' Services Incorporated Foundation | |
Research Promotion Foundation | |
Russian Academy of Sciences | |
Russian Foundation for Basic Research | |
Science and Technology Facilities Council | |
Swiss National Science Foundation | |
University of Malaya | |
National Science Foundation | 1306040, 1151640, 1306953, 1314131, 0906479, 1306951, 1205960, 1120138 |
Science and Technology Facilities Council | ST/L00609X/1, ST/I505572/1, ST/I005912/1, ST/J005665/1, ST/J004901/1, ST/K001256/1, ST/K003844/1, ST/L006340/1, GRIDPP, ST/F007094/1 |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | 146730, 153664 |
Keywords
- Large detectorsystems performance
- Pattern recognition, cluster finding, calibration and fitting methods
- Performance of High Energy Physics Detectors