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

Abstract

We examine the constraints on the trilinear Higgs coupling $\lambda$ that originate from associated ($Vh$) 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 $pp\to Vh$ and $pp\to jjh$ that stem from insertions of the dimension-6 operator $O_6=-\lambda {\left(H^{†}H\right)}^3$ are calculated and combined with the $\mathcal{O}(\lambda )$ 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 $\lambda$. We show that future LHC runs may be able to probe modifications of $\lambda$ 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 $h^3$ coupling is also studied.

Comments: 23 pages, 7 figures; v2: matches published version