Expected tracking performance of the ATLAS Inner Tracker at the High-Luminosity LHC

Abstract

The high-luminosity phase of LHC operations (HL-LHC), will feature a large increase insimultaneous proton-proton interactions per bunch crossing up to 200, compared with a typical levelingtarget of 64 in Run 3. Such an increase will create a very challenging environment in which to performcharged particle trajectory reconstruction, a task crucial for the success of the ATLAS physics program,and will exceed the capabilities of the current ATLAS Inner Detector (ID). A new all-silicon InnerTracker (ITk) will replace the current ID in time for the start of the HL-LHC. To ensure successfuluse of the ITk capabilities in Run 4 and beyond, the ATLAS tracking software has been successfullyadapted to achieve state-of-the-art track reconstruction in challenging high-luminosity conditions withthe ITk detector. This paper presents the expected tracking performance of the ATLAS ITk based onthe latest available developments since the ITk technical design reports.