The measurement of charge particle trajectories with the inner tracking detectors at the ATLAS experiment is a key input for higher-level object reconstructions, ranging from leptons to the identification of heavy-flavor jets. In addition the information provided by the inner tracking systems has been proven to be very powerful for disentangling the effects of several interactions occurring in the same bunch crossing (pile-up). In this contribution, we will review the performance during the Run 1 data-taking and preparation for the next run in 2015. In particular, we will show how the knowledge of the passive material inside the inner tracking acceptance has been further studied to reduce the systematic errors on the tracking efficiency, with benefits for physics measurements. In addition, the developments in disentangling close-by tracks which naturally occur in the decay of very high-pT objects (e.g. taus, of close to the core of jets) will be presented. The ongoing upgrade of the ATLAS detector includes an extra silicon layer (IBL) in the inner tracking system; the preparation for the integration of the new hardware and its expected performance will be reviewed as well. Finally, it will be presented a brief report on recent developments of the tracking software aiming for speed and disk-space optimizations.
Collaboration ATLAS (CERN)