CMS Tracker commissioning using cosmic muon data

摘要

Many physics channels, and in particular those including top quarkproduction, produce b jets in the final state that need to be identified in an environ-ment dominated by backgrounds containing only light-quark jets. The tagging ofb-jets exploits the properties of b-hadrons such as large proper lifetime, large massand decays to final states with high charged-track multiplicities. Precise spatialreconstruction close to the interaction point and efficient track reconstruction arekey ingredients for all b-tagging algorithms. These rely on stable, low noise, lowoccupancy and highly efficient tracking detectors. This is a short review of studiesof CMS tracker performance carried out using cosmic ray data taken at the CERNCMS Tracker Integration Facility between March and July 2007, in which it is shownthat the tracker more than meets the requirements for reliable b-tagging.