Constraints on the trilinear Higgs coupling from vector boson fusion and associated Higgs production at the LHC

We examine the constraints on the trilinear Higgs coupling λ that originate from associated (V h) and vector boson fusion (VBF) Higgs production in pp collisions in the context of the Standard Model effective field theory. The 1-loop contributions to pp → Vh and pp → jjh that stem from insertions of the dimension-6 operator O₆ = −λ (H^†H)³ are calculated and combined with the O(λ) corrections to the partial decay widths of the Higgs boson. Employing next-to-next-to-leading order QCD predictions, we analyse the sensitivity of current and forthcoming measurements of the signal strengths in Vh and VBF Higgs production to changes in λ. We show that future LHC runs may be able to probe modifications of λ with a sensitivity similar to the one that is expected to arise from determinations of double-Higgs production. The sensitivity of differential Vh and VBF Higgs distributions to a modified h³ coupling is also studied.