Theory uncertainties of the irreducible background to VBF Higgs production

Abstract

Higgs boson production through gluon fusion in association with two jets is an irreducible background to Higgs boson production through vector boson fusion, one of the most important channels for analyzing and understanding the Higgs boson properties at the Large Hadron Collider. Despite a range of available simulation tools, precise predictions for the corresponding final states are notoriously hard to achieve. Using state-of-the-art fixed-order calculations as the baseline for a comparison, we perform a detailed study of similarities and differences in existing event generators. We provide consistent setups for the simulations that can be used to obtain identical parametric precision in various programs used by experiments. We find that NLO calculations for the two-jet final state are essential to achieve reliable predictions.

Figures (18)

• Figure 1: The rapidity distribution of the Higgs at NLO accuracy, computed with NNLOJet (red), Sherpa (blue), and Powheg Box (orange).
• Figure 2: Comparison of the inclusive event-generation setups MEPS@NLO and MiNNLO$_\text{PS}$ to the NNLOJet$H+1j$ NNLO prediction in the fiducial $H+2j$ phase space for the transverse momentum of the leading (left) and sub-leading (right) jet. Scale factors are derived from the NNLOJet Higgs rapidity distribution, computed at NLO precision. The 2-jet final state is predicted at NLO-accuracy by MEPS@NLO and NNLOJET, and at LO accuracy in MiNNLO$_\text{PS}$.
• Figure 3: Comparison of the inclusive event-generation setups MEPS@NLO and MiNNLO$_\text{PS}$ to the NNLOJet$H+1j$ NNLO prediction in the fiducial $H+2j$ phase space for the Higgs transverse momentum $p_{\mathrm{T},H}$ (top left), the dijet invariant mass (top right), the dijet rapidity separation $\Delta y_{jj}$ (bottom left), and the dijet azimuthal angle separation $\Delta\phi_{jj}$ (bottom right). Scale factors are derived from the NNLOJet Higgs rapidity distribution, computed at NLO precision. The 2-jet final state is predicted at NLO-accuracy by MEPS@NLO and NNLOJET, and at LO accuracy in MiNNLO$_\text{PS}$.
• Figure 4: Comparison of the Sherpa MC@NLO, Powheg Box + Pythia, and Powheg Box + Herwig$H+2j$ NLO+PS predictions to the NNLOJet$H+1j$ NNLO prediction in the fiducial $H+2j$ phase space for the transverse momentum of the leading (left) and sub-leading (right) jet. Scaling factors are derived from the NNLOJet Higgs rapidity distribution, computed at NLO precision. All predictions are NLO-accurate for the two jet final state. No non-perturbative corrections have been applied.
• Figure 5: Comparison of the Sherpa MC@NLO, Powheg Box + Pythia, and Powheg Box + Herwig$H+2j$ NLO+PS predictions to the NNLOJet$H+1j$ NNLO prediction in the fiducial $H+2j$ phase space for the Higgs transverse momentum $p_{\mathrm{T},H}$ (top left), the dijet invariant mass (top right), the dijet rapidity separation $\Delta y_{jj}$ (bottom left), and the dijet azimuthal angle separation $\Delta\phi_{jj}$ (bottom right). Scaling factors are derived from the NNLOJet Higgs rapidity distribution, computed at NLO precision. All predictions are NLO-accurate for the two jet final state. No non-perturbative corrections have been applied.