Speaker
Description
Understanding the shape of the Higgs potential and the nature of the electroweak phase transition in theories beyond the Standard Model requires experimental information on the trilinear Higgs boson self-coupling $\kappa_3$ and the quartic self-coupling $\kappa_4$. Although triple Higgs production suffers from small cross-section rates, it can establish the first experimental bounds on $\kappa_4$ and provide insights on $\kappa_3$, complementing di-Higgs production analyses. In this work, we consider the $6b$ and $4b2\tau$ decay modes of triple Higgs production at the HL-LHC, utilising efficient Graph Neural Network methodologies to maximise the statistical yield. We demonstrate the potential to impose constraints on both couplings beyond limits from perturbative unitarity. Furthermore, we discuss the prospects from triple Higgs production at upcoming high-energy lepton colliders operating at the TeV scale.
