Probing triple Higgs production via 4τ2b decay channel at a 100 TeV hadron collider

A bstract A comprehensive study of triple Higgs boson production in the 4 τ 2 b decay final state is performed for the first time at a future 100 TeV hadron collider. The analysis incorporates modified Higgs self-couplings via trilinear Higgs self-coupling c 3 and quartic Higgs self-coupling d 4 , enabling a model-independent investigation of potential new physics effects. Higgs bosons are reconstructed using both resolved and boosted techniques. To optimize sensitivity across different kinematic regions, we introduce a novel event categorization strategy based on the triple Higgs invariant mass spectrum and the multiplicity of boosted Higgs bosons. In addition to a traditional cut-based analysis, a Boosted Decision Tree (BDT) approach is employed to exploit multivariate correlations among kinematic observables, leading to a significant improvement in sensitivity. Our result demonstrates that the 4 τ 2 b channel provides a viable pathway for probing the Higgs quartic coupling, complementing the existing multi-Higgs production studies, and could reach 5 σ in significance for c 3 ≲ −1 and d 4 ≳ 10 in the scanned range.