Next-to-leading order jet distributions for Higgs boson production via weak-boson fusion

TL;DR

The paper addresses accurate NLO QCD predictions for Higgs production in weak-boson fusion at the LHC. It introduces a fully flexible NLO parton-level Monte Carlo using Catani–Seymour subtraction, enabling reliable calculations of jet distributions under WBF cuts. The key findings show modest QCD corrections to jet observables (mostly 5-10%, up to 30% in certain regions) with small residual scale and PDF uncertainties, yielding an overall theoretical precision around 4%. This work supports precise Higgs coupling measurements through WBF channels and lays groundwork for extending the method to other WBF processes.

Abstract

The weak-boson fusion process is expected to provide crucial information on Higgs boson couplings at the Large Hadron Collider at CERN. The achievable statistical accuracy demands comparison with next-to-leading order QCD calculations, which are presented here in the form of a fully flexible parton Monte Carlo program. QCD corrections are determined for jet distributions and are shown to be modest, of order 5 to 10% in most cases, but reaching 30% occasionally. Remaining scale uncertainties range from order 5% or less for distributions to below +-2% for the Higgs boson cross section in typical weak-boson fusion search regions.

Figures (8)

• Figure 1: Feynman graphs contributing to $\bar{q}Q\hbox{$\rightarrow$} \bar{q}QH$ at (a) tree level and (b) including virtual corrections to the upper quark line.
• Figure 2: Real emission contributions to Higgs boson production via weak-boson fusion. Corrections for the upper quark line only are shown: gluon radiation ((a) and (b)) and gluon initiated processes ((c) and (d)).
• Figure 3: Effect of QCD radiative corrections on the Higgs boson production cross section via WBF, as a function of the Higgs boson mass, $m_H$. Results are given at LO (black dotted) and at NLO for the $p_T$-method (solid red) and the $E$-method (dashed blue) for defining tagging jets. Panel (a) gives the total cross section within the cuts of Eqs. (\ref{['eq:cuts1']})--(\ref{['eq:cuts4']}). The corresponding scale dependence, for variation of $\mu_R$ and $\mu_F$ by a factor of 2, is shown in panel (b). See text for details.
• Figure 4: Variation of the total cross section, within cuts, due to errors in the parton distribution functions, as a function of $m_H$. The central solid line corresponds to the "best fit" CTEQ6M pdf, while the upper and lower curves define the pdf error band, which is determined from the 40 error eigenvectors in the CTEQ6M set (CTEQ6M101--CTEQ6M140), adding cross section deviations in quadrature.
• Figure 5: Transverse momentum distribution of the softer tagging jet for the the $p_T$-method (solid red) and the $E$-method (dashed blue) of defining tagging jets, for $m_H=120$ GeV. The right-hand panels give the $K$-factors (black dash-dotted line) and the scale variation of the NLO results. Solid colored curves correspond to $\mu_F=\mu_R=\xi Q_i$ and dashed colored curves are for $\mu_F=\mu_R=\xi m_H$ with $\xi=1/2$ and $2$.