Studies on event selection criteria for the non-resonant $HH\rightarrow b\bar{b}b\bar{b}$ decay channel

In this thesis, methods of event selection for non-resonant Di-Higgs production in proton-proton collisions are discussed and a comparison of the different trigger paths for the Compact Muon Solenoid (CMS) and ATLAS experiment is made.

An event selection based on selection criteria used by ATLAS experiment is applied to Monte Carlo simulated data for the CMS experiment, with a center-of-mass energy of $\sqrt{s}={13}\,\mathrm{TeV}$ and an integrated luminosity of $36\,\mathrm{fb^{-1}}$ , that only contains Di-Higgs events that decay exclusively via the dominant channel $H\!H\rightarrow b\bar{b}b\bar{b}$ . To determine the efficiency and purity, selection criteria are applied on the Monte Carlo simulated data sample, and the result is compared with the generator level information of the simulation.

Furthermore, the background rejection provided these criteria, namely the dominant QCD-multijet background and the sub-dominant $t\bar{t}$ background, are studied. Based on the expected signal and background rates, experimental upper limits for the non-resonant Di-Higgs cross section are studied.