• b-tagging
• BDT
• di-boson production
• double Higgs production
• Higgs Boson
• Higgs–strahlung
• HL-LHC
• MVA analysis
• tau leptons

The production of Higgs boson pairs (HH) at LHC is a rare process in the Standard Model (SM). The current size of the proton-proton collision dataset recorded at LHC does not allow the observation of this process and thus the High Luminosity LHC (HL-LHC) phase, scheduled to begin in 2030, will be of crucial importance for the research of Higgs boson pairs. The work presented in this thesis is dedicated to the study of Higgs boson pairs in the $b\bar{b}\tau^{+}\tau^{-}$ decay channel, which is one of the most sensitive for the di-Higgs research. One of the main objectives of my thesis is to reproduce and extend the HL-LHC extrapolation presented by the ATLAS Collaboration, considering also the impact of improvements in $b$-tagging and the identification of hadronically decaying $\tau$-leptons. The second objective of this thesis is to develop control regions targeting the production of Z boson pairs ($pp\rightarrow ZZ$) and the associated production of a Higgs boson with a Z boson ($pp\rightarrow ZH$) - all in the $b\bar{b}\tau^{+}\tau^{-}$ final state - as benchmark processes to assess the robustness and reliability of the $pp\rightarrow HH$ analysis strategy.