Determination of ATLAS Trigger Efficiency for Di-Higgs Production in the 1𝑙3𝜏 Channel

This project focuses on determining the ATLAS trigger efficiency for di-Higgs boson production in the 1ℓ3τ final state, which involves one light lepton (electron or muon) and three hadronically decaying tau leptons. The study is performed  within the ATLAS Common Analysis Framework (CAF), a ROOT-based platform with C++ bindings for streamlined nTuple data analysis. Using simulated datasets, relevant trigger paths are selected, and efficiencies are evaluated by comparing the number of events passing specific trigger conditions to the total number of generated events. By combining multiple trigger paths, an overall efficiency of approximately 99.8% with a statistical uncertainty of 0.1% was achieved, ensuring nearly complete signal acceptance.