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Title: Description and performance of track and primary-vertex reconstruction with the CMS tracker

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 tbar 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, ormore » dedicated tracking for electrons that takes into account bremsstrahlung.« less
Authors:
 [1]
  1. Yerevan Physics Institute (Armenia). et al.
Publication Date:
OSTI Identifier:
1182726
Report Number(s):
FERMILAB-PUB--14-166-CMS; CMS-TRK-11-001; CERN-PH-EP-2014-070
Journal ID: ISSN 1748-0221; arXiv eprint number arXiv:1405.6569; TRN: US1500509
Type:
Accepted Manuscript
Journal Name:
Journal of Instrumentation
Additional Journal Information:
Journal Volume: 9; Journal Issue: 10; Journal ID: ISSN 1748-0221
Publisher:
Institute of Physics (IOP)
Research Org:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
CMS Collaboration
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ALGORITHMS; BREMSSTRAHLUNG; CERN LHC; CHARGED PARTICLES; ELECTRONS; MUONS; PARTICLE RAPIDITY; PERFORMANCE; PROTON-PROTON INTERACTIONS; TRANSVERSE MOMENTUM