Phase-II Tracking for ITk with ACTS and Seach for ttHH(HH→4b) Production

The High-Luminosity Large Hadron Collider (HL-LHC) upgrade will boost the data collection capacity of LHC experiments, leading to more precise measurements of Standard Model (SM) phenomena. By studying the trilinear Higgs self-coupling and di-Higgs production, HL-LHC aims to constrain the Higgs potential. However, this update presents challenges, necessitating upgrades to detector components due to increased pile-up. The Inner Detector will be replaced with the Inner Tracker (ITk) which will benefits searches for di-Higgs, such as the ttHH production. The HL-LHC environment predicts up to 200 proton-proton collisions in one bunch crossing, demanding efficient track reconstruction methods. The ATLAS collaboration explores software optimisations, including the adoption of the Common Tracking Software toolkit (ACTS) to profit from thread-safe and high-performing software with good maintainability and flexibility