Next-to-leading order QCD corrections to Higgs boson production in association with a photon via weak-boson fusion at the LHC

TL;DR

This work delivers next-to-leading order QCD predictions for Higgs boson production in association with a central photon via weak-boson fusion, implemented in a flexible parton-level Monte Carlo with Frixione photon isolation. Real and virtual QCD contributions are computed and cross-checked with multiple independent methods, yielding small overall cross-section corrections but notable shape changes in certain observables. The NLO results reduce scale uncertainties to the few-percent level and reveal up to ~20% distortions in specific kinematic distributions, highlighting the importance of NLO accuracy for precision Higgs coupling studies in the Hγjj WBF channel. The study also demonstrates how two distinct cut strategies influence signal sensitivity and background suppression in LHC analyses.

Abstract

Higgs boson production in association with a hard central photon and two forward tagging jets is expected to provide valuable information on Higgs boson couplings in a range where it is difficult to disentangle weak-boson fusion processes from large QCD backgrounds. We present next-to-leading order QCD corrections to Higgs production in association with a photon via weak-boson fusion at a hadron collider in the form of a flexible parton-level Monte Carlo program. The QCD corrections to integrated cross sections are found to be small for experimentally relevant selection cuts, while the shape of kinematic distributions can be distorted by up to 20% in some regions of phase space. Residual scale uncertainties at next-to-leading order are at the few-percent level.

Figures (7)

• Figure 1: Feynman diagrams contributing to the Born process $us\to dcH\gamma$. Graphs analogous to (b), with the photon being emitted off the lower quark line, are not shown.
• Figure 2: Scale dependence of the integrated cross section within the inclusive cuts of Eq. (\ref{['eq:cuts-jet']}) and Eqs. (\ref{['eq:icuts-rik']})--(\ref{['eq:icuts-mjj']}) at LO and NLO for two different choices of $\mu_{0}$. Shown are curves for $\xi_\mathrm{F} = \xi$ at LO (black dots), $\xi_\mathrm{R}=\xi_\mathrm{F}=\xi$ at NLO (red solid), $\xi_\mathrm{F}=\xi$, $\xi_\mathrm{R}=1$ at NLO (blue dash-dot), and $\xi_\mathrm{R}=\xi$, $\xi_\mathrm{F}=1$ at NLO (green dashes).
• Figure 3: Rapidity separation [panel (a)] and invariant mass distribution of the two tagging jets [panel (b)] in EW $H \gamma j j$ production at the LHC with $\sqrt{S}=14$ TeV at LO (dashed black lines) and NLO (solid red lines), after the cuts of Eq. (\ref{['eq:cuts-jet']}) and Eqs. (\ref{['eq:icuts-rik']})--(\ref{['eq:icuts-mjj']}) are applied.
• Figure 4: Transverse momentum distribution of the hardest tagging jet in EW $H \gamma j j$ production at the LHC with $\sqrt{S}=14$ TeV and $\sqrt{S}=7$ TeV, respectively, at LO (dashed black line) and NLO (solid red line) [panels (a) and (c)] and relative corrections according to Eq. (\ref{['eq:delta']}) when the factorization and renormalization scales are varied in the range $Q_i/2\leq\mu_\mathrm{R}=\mu_\mathrm{F}\leq 2Q_i$ [panels (b) and (d)].
• Figure 5: Transverse momentum distribution of the photon in EW $H \gamma j j$ production at the LHC with $\sqrt{S}=14$ TeV at LO (dashed black line) and NLO (solid red line) [panel (a)] and relative corrections according to Eq. (\ref{['eq:delta']}) when the factorization and renormalization scales are varied in the range $Q_i/2\leq\mu_\mathrm{R}=\mu_\mathrm{F}\leq 2Q_i$ [panel (b)].