Performance of the ATLAS Transition Radiation Tracker in Run 1 of the LHC: tracker properties

Understand

The tracking performance parameters of the ATLAS Transition Radiation Tracker (TRT) as part of the ATLAS inner detector are described in this paper for different data-taking conditions in proton-proton, proton-lead and lead-lead collisions at the Large Hadron Collider (LHC).

• The performance is studied using data collected during the first period of LHC operation (Run 1) and is compared with Monte Carlo simulations.
• The performance of the TRT, operating with two different gas mixtures (xenon-based and argon-based) and its dependence on the TRT occupancy is presented.
• These studies show that the tracking performance of the TRT is similar for the two gas mixtures and that a significant contribution to the particle momentum resolution is made by the TRT up to high particle densities.