Higgs self-coupling measurements using deep learning in the bbbb final state

Measuring the Higgs trilinear self-coupling λ hhh is experimentally demanding but fundamental for understanding the shape of the Higgs potential. We present a comprehensive analysis strategy for the HL-LHC using di-Higgs events in the four b -quark channel ( hh → 4 b ), extending current methods in several directions. We perform deep learning to suppress the formidable multijet background with dedicated optimisation for BSM λ hhh scenarios. We compare the λ hhh constraining power of events using different multiplicities of large radius jets with a two-prong structure that reconstruct boosted h → bb decays. We show that current uncertainties in the SM top Yukawa coupling y t can modify λ hhh constraints by ∼ 20