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

TL;DR

This paper investigates how current and future LHC measurements of associated and vector boson fusion Higgs production can constrain the Higgs trilinear coupling, using effective field theory and higher-order QCD calculations.

Contribution

It provides a detailed analysis of the sensitivity of LHC Higgs production channels to modifications in the Higgs trilinear coupling within the Standard Model effective field theory framework.

Findings

Future LHC runs could probe Higgs self-coupling modifications similarly to double-Higgs production.

1-loop contributions from dimension-6 operators impact associated and VBF Higgs production.

Differential distributions offer additional sensitivity to the Higgs trilinear coupling.

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 $pp \to V h$ and $pp \to jj h$ that stem from insertions of the dimension-6 operator $O_6 = - \lambda \left (H^\dagger H \right )^3$ are calculated and combined with the ${\cal O} (\lambda)$ 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.