Higgs boson self-coupling constraints from single Higgs, double Higgs and electroweak measurements

We set constraints on the trilinear Higgs boson self-coupling, λ3 , by combining the information coming from the W mass and leptonic effective Weinberg angle, electroweak precision observables, with the single Higgs boson analyses targeting the γ γ , Z Z ∗ , W W ∗ , τ + τ − and b̄b decay channels and the double Higgs boson analyses in the bb̄bb̄ , bb̄ τ + τ − and bb̄ γ γ decay channels, performed by the ATLAS collaboration. With the assumption that the new physics affects only the Higgs potential, values outside SM the interval − 1 . 8 λ3 SM < λ3 < 9 . 2 λ3 SM are excluded at 95% confidence level. With respect to similar analyses that do not include the information coming from the electroweak precision observables our analysis shows a stronger constraint on both positive and negative values of λ3 .