Search for non-resonant di-Higgs production in the $b\bar{b}b\bar{b}$ final state at $\sqrt{s}=$13 TeV with the ATLAS experiment

Result is presented of the search for non-resonant di-Higgs production in the $b\bar{b}b\bar{b}$ final state √ using the Run-2 dataset of proton-proton collisions at $\sqrt{s}=13$ TeV accumulated with the ATLAS detector. The $b\bar{b}b\bar{b}$ final state is one of the most sensitive channels for measuring the Higgs self-coupling and the di-Higgs production cross-section, thanks to the highest branching ratio. The analysis utilizes a novel neural network to estimate the large QCD multijet backgrounds, and employs analysis categorizations to improve the sensitivity to the di-Higgs production. The analysis strategy and the latest result of the observed (expected) upper limits on the SM di-Higgs production cross-section and the constraint on the Higgs self-coupling at a 95% confidence in this analysis are presented.