2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44221We calculate both the cubic and the quartic self-couplings of the lighter scalar Higgs boson without assuming the decoupling limit in the two-Higgs-doublet model (THDM). In some regions of parameter space of the THDM where the electroweak phase transition is strongly first order, it is possible that the quartic self-coupling of the lighter scalar Higgs boson might be deviated by at least 40 % from the standard model prediction.5 pages, 1 figureHigh Energy Physics - Phenomenologytext