Higgs production on Vector Boson Fusion at NNLO QCD in NNLOjet Juan - - PowerPoint PPT Presentation

Higgs production on Vector Boson Fusion at NNLO QCD in NNLOjet

Juan M Cruz-Martinez in collaboration with: T. Gehrmann, N. Glover, A. Huss arXiv:1802.02445

IPPP Durham University HL-HE LHC Workshop

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 1 / 6

Vector Boson Fusion amplitudes

We work on what is usually known as the DIS approach, which means defining “Vector Boson Fusion” as: Diagrams in which the vector boson is exchanged in the t channel Not including exchange of gluons between upper and lower legs (either real or virtual). Not including same flavour quark annihilation These contributions are estimated to be negligible when VBF cuts are applied1.

1See, for instance arXiv:1802.09955 Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 2 / 6

Current status

We re-implemented all Matrix Elements necessary for the DIS approximation, ie, forbidding colour flow between the two legs. We use Antenna Subtraction to control divergences. Implemented in NNLOjet, which provides all analysis routines, antenna functions and integration machinery. Results and plots from: arXiv:1802.02445 We find good agreement with arXiv:1506.02660v2, see backup slides / A. Karlberg talk.

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 3 / 6

Observables, VBF at NNLO

10-1 100 101 NNLOJET

√s ‾ = 13 TeV

dσ/dpT

j1[fb/GeV]

VBF H 2j NNLO

LO NLO NNLO 0.8 0.9 1 1.1 50 100 150 200 250 300 NNLOJET

√s ‾ = 13 TeV

Ratio to NLO pT

j1 [GeV]

100 200 300 400 500 NNLOJET

√s ‾ = 13 TeV

dσ/dΔyjj [fb]

VBF H 2j NNLO

LO NLO NNLO 0.8 0.9 1 1.1 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 NNLOJET

√s ‾ = 13 TeV

Ratio to NLO Δyjj

Figure: For some observables the NNLO corrections alter the shape of the distributions, albeit their effect is much less than NLO.

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 4 / 6

Observables, VBF at NNLO

100 200 300 400 NNLOJET

√s ‾ = 13 TeV

dσ/dΦj12[fb]

VBF H 2j NNLO

LO NLO NNLO 0.8 0.9 1 1.1 180 45 90 135 NNLOJET

√s ‾ = 13 TeV

Ratio to NLO Φj12 [deg] 0.2 0.4 0.6 0.8 1 NNLOJET

√s ‾ = 13 TeV

dσ/dMjj[fb/GeV]

VBF H 2j NNLO

LO NLO NNLO 0.8 0.9 1 1.1 1000 2000 3000 4000 NNLOJET

√s ‾ = 13 TeV

Ratio to NLO Mjj [GeV]

Figure: For these observables we don’t see a change on the shape but the NNLO contributions falls consistently outside the NLO uncertainty bands.

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 5 / 6

Future work

Proper studies of Higgs production through the VBF production channel requires NNLO corrections. We have implemented NNLO QCD corrections to VBF Higgs alongside the other processes in NNLOjet. Other things we could add to our implementation include: Decay channels for the Higgs (H → γγ, H → b¯ b, H → WW ∗...). Multiple Higgs production (very small for 13 TeV, maybe relevant for high energies) Suggestions welcomed.

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 6 / 6

Backup slides

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 7 / 6

Vector Boson Fusion: VBF Cuts

Two tagging jets with pT > 25 GeV Tagging jets in different hemisphere (y1y2 < 0) where each yi > 4.5 and ∆y12 > 4.5 µ2

0(pT,H) = MH

2 MH 2 2 + p2

t,H

mjj > 600 GeV √s = 13 TeV MH = 125 GeV Scale variations corresponds to µF = µR = 1

2, 1, 2

• µ0.

PDF used: NNPDF30 nnlo as 0118

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 8 / 6

Total cross section with VBF cuts

Comparison with 1506.02660v22: σ1506.02660 (fb) σNNLOjet (fb) LO 957+66

−59

957+66

−59

NLO 876+8

−18

877+7

−17

NNLO 844+8

−8

844+9

−9

Table: Total cross section with VBF cuts. The errors correspond to a scale variation of µF = µR = 1

2, 1, 2

• µ0.

We also find good agreement comparing differential distributions.

2M.Cacciari, F.A.Dreyer, A.Karlberg, G.P.Salam and G.Zanderighi. “Fully

Differential Vector-Boson-Fusion Higgs Production at Next-to-Next-to-Leading Order” PRL 115.082002

Juan Cruz-Martinez (IPPP) VBF H in NNLOjet 9 / 6