Development of ATLAS ITk tracking software & applicability of improved tracking to searches for long-lived supersymmetric particles in Run 3&4 at LHC

The track reconstruction in the upgraded ATLAS tracker, the ITk, is crucial. During their PhD, the student is expected to study in detail the performance of the ITk, working on the tracking software together with experts at Liverpool and DESY. As benchmark to evaluate the tracking performance of the ITk and optimise the tracking software, the student will focus on the search for dark matter candidates as predicted in supersymmetric models where the mass splitting between electroweak supersymmetric particles is below 1 GeV. These scenarios will be one of the "hot topics" of the HL-LHC studies as there is very limited sensitivity at the LHC. In these scenarios the charged lightest SUSY particle decays within the innermost tracking detector gives rise to a disappearing track signature. An in-depth understanding of the tracking performance is crucial and the student will be best placed to also contribute to the Run 3 analysis on real data expected to be completed by 2022-2023. The student will be a core member of the ATLAS tracking software team, focusing on the ITk software. They will be able to link directly this understanding to the physics prospects of a new detector.