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Electroweak Corrections to Higgs Production Alexander Mck RWTH Aachen University Workshop on electroweak corrections for LHC physics Durham, September 25, 2012 | | EW Corrections to Higgs Production Alexander M uck

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EW Corrections to Higgs Production – Alexander M¨ uck – p.1/ 24

←→

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⇐ ⇒

Electroweak Corrections to Higgs Production

Alexander Mück RWTH Aachen University

Workshop on electroweak corrections for LHC physics Durham, September 25, 2012

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.2/ 24

Outline

←→

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⇐ ⇒

Introduction (a few general remarks) Channels:

Gluon fusion Vector-boson fusion (VBF) Higgsstrahlung (WH/ZH)

(personal bias towards VBF and WH/ZH)

Higgs decays

Electroweak corrections:

available calculations (tools) size ⇔ relevance ⇔ QCD uncertainties total cross sections ⇔ distributions

Summary

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.3/ 24

The new boson

←→

| |

⇐ ⇒

) µ Signal strength (

  • 1 0 1

Combined 4l →

(*)

ZZ → H γ γ → H ν l ν l →

(*)

WW → H τ τ → H bb → W,Z H

  • 1

Ldt = 4.6 - 4.8 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.8 - 5.9 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.8 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.8 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.8 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.9 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.7 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.8 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.7 fb

∫

= 7 TeV: s

  • 1

Ldt = 4.6-4.7 fb

∫

= 7 TeV: s

= 126.0 GeV

H

m

0.3 ± = 1.4 µ

ATLAS 2011 - 2012

H SM

σ / σ Best fit

  • 6
  • 4
  • 2

2 4 6 8 ZZ → H WW (VH tag) → H WW (VBF tag) → H WW (0/1 jet) → H (VBF tag) γ γ → H (untagged) γ γ → H (VH tag) τ τ → H (VBF tag) τ τ → H (0/1 jet) τ τ → H bb (ttH tag) → H bb (VH tag) → H CMS Preliminary

  • 1

= 7 TeV, L = 5.1 fb s

  • 1

= 8 TeV, L = 5.3 fb s = 125 GeV

H

m

ATLAS-CONF-2012-127 CMS-HIG-12-020

Is it the SM Higgs boson? (spin, CP even/odd, anomalous couplings, etc. )

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.3/ 24

The new boson

←→

| |

⇐ ⇒

) µ Signal strength (

  • 1 0 1

Combined 4l →

(*)

ZZ → H γ γ → H ν l ν l →

(*)

WW → H τ τ → H bb → W,Z H

  • 1

Ldt = 4.6 - 4.8 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.8 - 5.9 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.8 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.8 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.8 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.9 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.7 fb

∫

= 7 TeV: s

  • 1

Ldt = 5.8 fb

∫

= 8 TeV: s

  • 1

Ldt = 4.7 fb

∫

= 7 TeV: s

  • 1

Ldt = 4.6-4.7 fb

∫

= 7 TeV: s

= 126.0 GeV

H

m

0.3 ± = 1.4 µ

ATLAS 2011 - 2012

H SM

σ / σ Best fit

  • 6
  • 4
  • 2

2 4 6 8 ZZ → H WW (VH tag) → H WW (VBF tag) → H WW (0/1 jet) → H (VBF tag) γ γ → H (untagged) γ γ → H (VH tag) τ τ → H (VBF tag) τ τ → H (0/1 jet) τ τ → H bb (ttH tag) → H bb (VH tag) → H CMS Preliminary

  • 1

= 7 TeV, L = 5.1 fb s

  • 1

= 8 TeV, L = 5.3 fb s = 125 GeV

H

m

ATLAS-CONF-2012-127 CMS-HIG-12-020

Is it the SM Higgs boson? (spin, CP even/odd, anomalous couplings, etc. ) EW corrections calculated in the (MS)SM (⇒ assume the new boson is the SM Higgs and search for deviations) QCD corrections might be more universal

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.4/ 24

EW corrections

←→

| |

⇐ ⇒

generic size:

expect percent level corrections

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.4/ 24

EW corrections

←→

| |

⇐ ⇒

generic size:

expect percent level corrections 5-10% in Higgs production

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.4/ 24

EW corrections

←→

| |

⇐ ⇒

generic size:

expect percent level corrections 5-10% in Higgs production naive comparison with QCD: O(α) ∼ O(α2

s)

⇒ needed for high precision observables (with small QCD uncertainties) ⇒ vector-boson fusion

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.4/ 24

EW corrections

←→

| |

⇐ ⇒

generic size:

expect percent level corrections 5-10% in Higgs production naive comparison with QCD: O(α) ∼ O(α2

s)

⇒ needed for high precision observables (with small QCD uncertainties) ⇒ vector-boson fusion (logarithmically) enhanced EW corrections: at high energies: Sudakov logs ∝ α → α log2(Q/MV )) in peaked distribution from photon radiation

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.4/ 24

EW corrections

←→

| |

⇐ ⇒

generic size:

expect percent level corrections 5-10% in Higgs production naive comparison with QCD: O(α) ∼ O(α2

s)

⇒ needed for high precision observables (with small QCD uncertainties) ⇒ vector-boson fusion (logarithmically) enhanced EW corrections: at high energies: Sudakov logs ∝ α → α log2(Q/MV )) in peaked distribution from photon radiation ⇒ boosted Higgs in WH/ZH

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.5/ 24

EW corrections

←→

| |

⇐ ⇒

Generic features:

relative EW correction rather independent of: collider energy (QCD) scale choices PDF choice EW effects neglected in PDFs O(1%) contribution from photons in initial state

(estimated from MRST2004 PDF)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.6/ 24

QCD and EW corrections

←→

| |

⇐ ⇒

How to combine QCD and EW corrections?

additive: σbest = σLO(1 + δQCD + δEW) ? factorized: σbest = σQCD

best (1 + δEW) ?

difference is of higher order

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.6/ 24

QCD and EW corrections

←→

| |

⇐ ⇒

How to combine QCD and EW corrections?

additive: σbest = σLO(1 + δQCD + δEW) ? factorized: σbest = σQCD

best (1 + δEW) ?

difference is of higher order

Factorized approximation is commonly used

assumptions: QCD corrections dominated by soft-collinear physics EW corrections in underlying hard process or FSR

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.7/ 24

Higgs cross sections

←→

| |

⇐ ⇒

LHC Higgs cross section working group:

https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections Yellow reports: 1101.0593 and 1201.3084

[GeV]

H

M 80 100 200 300 400 1000 H+X) [pb] → (pp σ

  • 2

10

  • 1

10 1 10

2

10 = 8 TeV s

LHC HIGGS XS WG 2012

H (NNLO+NNLL QCD + NLO EW) → pp qqH (NNLO QCD + NLO EW) → pp WH (NNLO QCD + NLO EW) → pp ZH (NNLO QCD +NLO EW) → pp ttH (NLO QCD) → pp

[GeV]

H

M 100 120 140 160 180 200 Higgs BR + Total Uncert

  • 3

10

  • 2

10

  • 1

10 1

LHC HIGGS XS WG 2011

b b τ τ c c gg γ γ γ Z WW ZZ

joint effort to provide best predictions for cross sections and distributions EW corrections included where available

  • ngoing effort: EW corrections in differential analysis

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.8/ 24

Gluon-Fusion

←→

| |

⇐ ⇒ h0 t t t

dominant production process at LHC enormous efforts for the QCD prediction NNLO, resummation . . . uncertainty O(20%)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.8/ 24

Gluon-Fusion

←→

| |

⇐ ⇒ h0 t t t

dominant production process at LHC enormous efforts for the QCD prediction full NLO (2-loop) EW corrections

H g g W, Z

Actis, Passarino, Sturm, Uccirati [arXiv:0809.1301]

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.8/ 24

Gluon-Fusion

←→

| |

⇐ ⇒ h0 t t t

dominant production process at LHC enormous efforts for the QCD prediction full NLO (2-loop) EW corrections

−4 −2 2 4 6 δEW [%] δEW [%] 100 150 200 250 300 350 400 450 500 MH [GeV] MH [GeV]

1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 100 150 200 250 300 350 400 450 500 K factor MH [GeV] pp → H + X √s = 14 TeV − MRST 2002 NNLO QCD NNLO QCD + NLO EW

Actis, Passarino, Sturm, Uccirati [arXiv:0809.1301]

non-trivial threshold behaviour inside loops (WW,ZZ,t¯

t)

⇒ complex-mass scheme at two loops

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.8/ 24

Gluon-Fusion

←→

| |

⇐ ⇒ h0 t t t

dominant production process at LHC enormous efforts for the QCD prediction full NLO (2-loop) EW corrections mixed O(ααs) corrections (light fermion loops)

Anastasiou, Boughezal, Petriello [arXiv:0811.3458]

H g g W, Z

⇒ effective theory approach

(corrections to Wilson coefficient in effective ggH coupling)

⇒ same philosophy like for QCD corrections

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.8/ 24

Gluon-Fusion

←→

| |

⇐ ⇒ h0 t t t

dominant production process at LHC enormous efforts for the QCD prediction full NLO (2-loop) EW corrections mixed O(ααs) corrections (light fermion loops)

Anastasiou, Boughezal, Petriello [arXiv:0811.3458]

  • 2

2 4 6 8 110 120 130 140 150 160 170 180

δEW [%] mH [GeV] LHC

LO NLO NNLO, C2W = -10 NNLO, C2W = 10 NNLO CF

∼5% correction at MH =125 GeV supports factorization

  • f EW and QCD corrections

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.9/ 24

Vector-Boson Fusion

←→

| |

⇐ ⇒

q q q q H V V q q q q H V V q q q q H V V

q¯ q → Hjj

sizeable fraction of inclusive Higgs production special kinematics: forward and backward jet ⇒ VBF signal VBF cuts on jets (pT, y, rapidity gap, central jet veto) to reduce background to separate from gg → Hjj in gluon fusion (5% after cuts) s-channel and interferences negligible (DIS2 like process) measure HWW and HZZ couplings investigate non-standard couplings

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.10/ 24

Vector-Boson Fusion

←→

| |

⇐ ⇒

State of the art: Inclusive cross section

σ (pb) at LHC √s = 7 TeV scale choice: Q/4 ≤ µR,µF ≤ 4Q LO NLO NNLO 10

  • 1

1 10

  • 1

1 σ(µR,µF)/σNNLO(Q) 0.92 0.96 1 1.04 1.08 100 150 200 250 300 350 400 450 500 mH(GeV)

NNLO QCD corrections: VBF@NNLO

Bolzoni,Maltoni,Moch,Zaro [arXiv:1003.4451]

structure function approach (→ DIS2) QCD under excellent theoretical control at the 1% level

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.10/ 24

Vector-Boson Fusion

←→

| |

⇐ ⇒

State of the art: Inclusive cross section

σ (pb) at LHC √s = 7 TeV scale choice: Q/4 ≤ µR,µF ≤ 4Q LO NLO NNLO 10

  • 1

1 10

  • 1

1 σ(µR,µF)/σNNLO(Q) 0.92 0.96 1 1.04 1.08 100 150 200 250 300 350 400 450 500 mH(GeV)

NNLO QCD corrections: VBF@NNLO

Bolzoni,Maltoni,Moch,Zaro [arXiv:1003.4451]

structure function approach (→ DIS2) QCD under excellent theoretical control at the 1% level EW corrections relevant

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.11/ 24

Vector-Boson Fusion

←→

| |

⇐ ⇒

State of the art: fully differential predictions

NLO QCD+EW corrections available in public codes

VBFNLO

(latest release: Arnold et al. [1207.4975])

s-channel and interferences neglected EW corrections in the MSSM many additional features HAWK

(Denner, Dittmaier, Kallweit, AM) Ciccolini,Dittmaier, Krämer [hep-ph/0306234]

no kinematic limitations (s-channel and interferences included)

http://omnibus.uni-freiburg.de/∼sd565/programs/hawk/hawk.html

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.11/ 24

Vector-Boson Fusion

←→

| |

⇐ ⇒

State of the art: fully differential predictions

NLO QCD+EW corrections available in public codes

VBFNLO

(latest release: Arnold et al. [1207.4975])

s-channel and interferences neglected EW corrections in the MSSM many additional features HAWK

(Denner, Dittmaier, Kallweit, AM) Ciccolini,Dittmaier, Krämer [hep-ph/0306234]

no kinematic limitations (s-channel and interferences included)

Beyond fixed order Powheg: merging NLO QCD with PS

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.12/ 24

Total cross section

←→

| |

⇐ ⇒

[GeV]

H

M 100 200 300 400 500 600 700 800 900 1000 qqH) [pb] → (pp σ

−2

10

−1

10 1

MSTW2008 − 7 TeV NLO QCD + NLO EW MSTW2008 − 7 TeV NNLO QCD + NLO EW

LHC HIGGS XS WG 2010

O(5%) QCD corrections small uncertainties: scale: < 1% (for MH < 250 GeV) PDF+αs: < 4% (for MH < 300 GeV) O(-5%) EW corrections σ = σNNLO(1 + δEW)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.12/ 24

Total cross section

←→

| |

⇐ ⇒

[GeV]

H

M 100 200 300 400 500 600 700 800 900 1000 qqH) [pb] → (pp σ

−2

10

−1

10 1

MSTW2008 − 7 TeV NLO QCD + NLO EW MSTW2008 − 7 TeV NNLO QCD + NLO EW

LHC HIGGS XS WG 2010

O(5%) QCD corrections small uncertainties: scale: < 1% (for MH < 250 GeV) PDF+αs: < 4% (for MH < 300 GeV) O(-5%) EW corrections σ = σNNLO(1 + δEW) so far:

no VBF cuts, but no s-channel contribution ⇒ need for differential predictions (including cuts)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.13/ 24

VBF cuts

←→

| |

⇐ ⇒

Setup from second Yellow report (1201.3084): Selection cuts: pTj > 20 GeV |yj| < 4.5 VBF cuts: |yj1 − yj2| > 4 Mjj > 600 GeV

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.13/ 24

VBF cuts

←→

| |

⇐ ⇒

Setup from second Yellow report (1201.3084): Selection cuts: pTj > 20 GeV |yj| < 4.5 VBF cuts: |yj1 − yj2| > 4 Mjj > 600 GeV ⇒ for MH = 125 GeV: EW correction:

δEW = −8%

scale uncertainty: ∼ 0.5% PDF uncertainty: ∼ 3.5%

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.14/ 24

Distributions

←→

| |

⇐ ⇒

example: azimuthal angle between tagging jets

Hankele, Klämke, Zeppenfeld [hep-ph/0609075]

0.002 0.004 0.006 0.008 0.01 0.012 0.014 40 80 120 160 1/ σ dσ / d ∆φjj |∆φjj| CP-even CP-odd SM 0.0045 0.005 0.0055 0.006 0.0065 0.007 40 80 120 160 1/ σ dσ / d |∆φjj| |∆φjj| CP-even + CP-odd SM

⇒ shape difference as signal for new physics What about higher order corrections in distribution?

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.15/ 24

Distributions

←→

| |

⇐ ⇒

example: azimuthal angle between tagging jets

Ciccolini,Dittmaier, Krämer [hep-ph/0306234]

QCD EW EW+QCD

MH = 120 GeV pp → Hjj + X ∆φjj

dσ dσLO − 1 [%]

180 135 90 45 −2 −4 −6 −8 −10 −12 −14

NLO QCD corrections rather flat NLO EW corrections distort shape

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.15/ 24

Distributions

←→

| |

⇐ ⇒

example: azimuthal angle between tagging jets

Ciccolini,Dittmaier, Krämer [hep-ph/0306234]

QCD EW EW+QCD

MH = 120 GeV pp → Hjj + X ∆φjj

dσ dσLO − 1 [%]

180 135 90 45 −2 −4 −6 −8 −10 −12 −14

NLO QCD corrections rather flat NLO EW corrections distort shape ⇒ differential reweighting to combine with best QCD prediction

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.16/ 24

Higgsstrahlung

←→

| |

⇐ ⇒

u/d d/u H W W± q q H Z Z t g g H Z

pp → W/Z + H

  • nly small fraction of total Higgs cross section

for a 125 GeV Higgs H → b¯ b should be accessible small signal to background ratio ⇒ boosted Higgs: use high pT Higgs bosons only b jets from "fat jet" substructure QCD corrections similar to Drell-Yan (→ relatively simple) additional gluon-fusion contribution (5% level) EW corrections more involved

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.17/ 24

Higgsstrahlung

←→

| |

⇐ ⇒

State of the art before 2011: Inclusive cross section

NNLO QCD corrections: VH@NNLO

Brein, Djouadi, Harlander [hep-ph/0307206]

  • nly for total cross section

NLO EW corrections

Ciccolini,Dittmaier, Krämer [hep-ph/0306234]

  • nly for total cross section

stable W/Z bosons

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.17/ 24

Higgsstrahlung

←→

| |

⇐ ⇒

State of the art before 2011: Inclusive cross section

NNLO QCD corrections: VH@NNLO

Brein, Djouadi, Harlander [hep-ph/0307206]

NLO EW corrections

Ciccolini,Dittmaier, Krämer [hep-ph/0306234]

scale uncertainty: 1-2 % @ NNLO PDF+αs uncertainty: 3-5% EW correction: -5% for ZH and -7% for WH (at MH = 125 GeV)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.17/ 24

Higgsstrahlung

←→

| |

⇐ ⇒

State of the art before 2011: Inclusive cross section

NNLO QCD corrections: VH@NNLO

Brein, Djouadi, Harlander [hep-ph/0307206]

NLO EW corrections

Ciccolini,Dittmaier, Krämer [hep-ph/0306234] σWH = σVH@NNLO

WH

×(1+δWH,EW) , σZH = σVH@NNLO

ZH

×(1+δZH,EW)+σgg→ZH ,

[GeV]

H

M 100 150 200 250 300 WH) [pb] → (pp σ

  • 1

10 1

= 14 TeV s = 7 TeV s

LHC HIGGS XS WG 2010

NNLO QCD + NLO EW

[GeV]

H

M 100 150 200 250 300 WH) NNLO / LO → (pp σ 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4

= 7 TeV s ) σ 1 ± NNLO / LO ( ) σ 2 ± NNLO / LO (

LHC HIGGS XS WG 2010

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.17/ 24

Higgsstrahlung

←→

| |

⇐ ⇒

State of the art before 2011: Inclusive cross section

NNLO QCD corrections: VH@NNLO

Brein, Djouadi, Harlander [hep-ph/0307206]

NLO EW corrections

Ciccolini,Dittmaier, Krämer [hep-ph/0306234]

not applicable for boosted Higgs analysis

(very specific phase space region)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.18/ 24

Recent developments

←→

| |

⇐ ⇒

Differential NNLO QCD for WH

Ferrera, Grazzini, Tramontano [arXiv:1107.1164]

fully differential Drell-Yan like NNLO QCD contributions including Higgs and vector-boson decays H → b¯ b analysis possible (b-tagging, jet veto, etc...)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.18/ 24

Recent developments

←→

| |

⇐ ⇒

Differential NNLO QCD for WH

Ferrera, Grazzini, Tramontano [arXiv:1107.1164]

large negative correction due to strict jet veto

EW Corrections to Higgs Production – p. 0/ 24

slide-38
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EW Corrections to Higgs Production – Alexander M¨ uck – p.18/ 24

Recent developments

←→

| |

⇐ ⇒

Differential NNLO QCD for WH

Ferrera, Grazzini, Tramontano [arXiv:1107.1164]

NNLO beyond Drell-Yan

Brein, Harlander, Wiesemann, Zirke [arXiv:1111.0761]

two-loop contribution in heavy-top limit inclusive prediction only

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.19/ 24

Differential NLO EW

←→

| |

⇐ ⇒

WH/ZH implemented in HAWK:

Denner, Dittmaier, Kallweit, Mück [1112.5142]

fully differential EW corrections for the processes pp → Hl+l−, pp → Hlνl, pp → H¯ νlνl

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 40

EW Corrections to Higgs Production – Alexander M¨ uck – p.19/ 24

Differential NLO EW

←→

| |

⇐ ⇒

WH/ZH implemented in HAWK:

Denner, Dittmaier, Kallweit, Mück [1112.5142]

fully differential EW corrections for the processes pp → Hl+l−, pp → Hlνl, pp → H¯ νlνl full access to leptons in final state

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.19/ 24

Differential NLO EW

←→

| |

⇐ ⇒

WH/ZH implemented in HAWK:

Denner, Dittmaier, Kallweit, Mück [1112.5142]

fully differential EW corrections for the processes pp → Hl+l−, pp → Hlνl, pp → H¯ νlνl full access to leptons in final state vector-boson resonance ⇒ use the complex mass scheme

(will also regularize threshold spikes in EW corrections)

EW Corrections to Higgs Production – p. 0/ 24

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EW Corrections to Higgs Production – Alexander M¨ uck – p.19/ 24

Differential NLO EW

←→

| |

⇐ ⇒

WH/ZH implemented in HAWK:

Denner, Dittmaier, Kallweit, Mück [1112.5142]

fully differential EW corrections for the processes pp → Hl+l−, pp → Hlνl, pp → H¯ νlνl full access to leptons in final state vector-boson resonance ⇒ use the complex mass scheme

(will also regularize threshold spikes in EW corrections)

HAWK for VBF includes s-channel contribution ⇒ replace hadronic by leptonic boson decay independent second calculation HAWK for WH/ZH will also be public

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 43

EW Corrections to Higgs Production – Alexander M¨ uck – p.20/ 24

Setup

←→

| |

⇐ ⇒ WH results: NNLO QCD from the authors of 1107.1164 NLO EW from HAWK ZH results: NLO QCD and EW from HAWK QCD and EW corrections combined in factorized form: σ = σQCD × (1 + δrec

EW) + δγ

EW Corrections to Higgs Production – p. 0/ 24

slide-44
SLIDE 44

EW Corrections to Higgs Production – Alexander M¨ uck – p.20/ 24

Setup

←→

| |

⇐ ⇒ WH results: NNLO QCD from the authors of 1107.1164 NLO EW from HAWK ZH results: NLO QCD and EW from HAWK all results for 8 TeV LHC all results for MH = 120 GeV

  • n-shell Higgs without decay

for MH = 125 GeV results for EW corrections differ only by roughly 0.2%

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 45

EW Corrections to Higgs Production – Alexander M¨ uck – p.20/ 24

Setup

←→

| |

⇐ ⇒ WH results: NNLO QCD from the authors of 1107.1164 NLO EW from HAWK ZH results: NLO QCD and EW from HAWK all results for 8 TeV LHC all results for MH = 120 GeV

  • ff-shell vector bosons with leptonic decay

all results for specific leptonic channel different lepton–photon recombination for µ and e

EW Corrections to Higgs Production – p. 0/ 24

slide-46
SLIDE 46

EW Corrections to Higgs Production – Alexander M¨ uck – p.20/ 24

Setup

←→

| |

⇐ ⇒ WH results: NNLO QCD from the authors of 1107.1164 NLO EW from HAWK ZH results: NLO QCD and EW from HAWK all results for 8 TeV LHC all results for MH = 120 GeV

  • ff-shell vector bosons with leptonic decay

cuts for boosted Higgs bosons: pT,l > 20 GeV, |yl| < 2.5, pT,miss > 25 GeV pT,H > 200 GeV, pT,W/Z > 190 GeV

(avoid symmetric cuts)

EW Corrections to Higgs Production – p. 0/ 24

slide-47
SLIDE 47

EW Corrections to Higgs Production – Alexander M¨ uck – p.20/ 24

Setup

←→

| |

⇐ ⇒ WH results: NNLO QCD from the authors of 1107.1164 NLO EW from HAWK ZH results: NLO QCD and EW from HAWK all results for 8 TeV LHC all results for MH = 120 GeV

  • ff-shell vector bosons with leptonic decay

cuts for boosted Higgs bosons: pT,l > 20 GeV, |yl| < 2.5, pT,miss > 25 GeV pT,H > 200 GeV, pT,W/Z > 190 GeV

(avoid symmetric cuts)

central scale choice: µF = µR = MH + MV default PDF set: MSTW2008

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 48

EW Corrections to Higgs Production – Alexander M¨ uck – p.21/ 24

Results

←→

| |

⇐ ⇒

H l−¯ ν H l+ν

pT,H[GeV] dσ/dpT,H[fb/GeV]

300 280 260 240 220 200 0.025 0.02 0.015 0.01 0.005

LHC Higgs XS WG 2012

H ν¯ ν H l+l−

pT,H[GeV] dσ/dpT,H[fb/GeV]

300 280 260 240 220 200 0.025 0.02 0.015 0.01 0.005

LHC Higgs XS WG 2012

H l−¯ ν H l+ν

pT,V[GeV] dσ/dpT,V[fb/GeV]

300 280 260 240 220 200 0.02 0.015 0.01 0.005

LHC Higgs XS WG 2012

H ν¯ ν H l+l−

pT,V[GeV] dσ/dpT,V[fb/GeV]

300 280 260 240 220 200 0.02 0.015 0.01 0.005

LHC Higgs XS WG 2012

σ = σQCD × (1 + δrec

EW) + δγ

NNLO: green, blue NLO: red, black

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 49

EW Corrections to Higgs Production – Alexander M¨ uck – p.22/ 24

EW corrections

←→

| |

⇐ ⇒

δbare

H l−¯ ν

δrec

H l−¯ ν

δbare

H l+ν

δrec

H l+ν

pT,H[GeV] δEW[%]

300 280 260 240 220 200 −5 −10 −15 −20

LHC Higgs XS WG 2012

δH ν¯

ν

δbare

H l+l−

δrec

H l+l−

pT,H[GeV] δEW[%]

300 280 260 240 220 200 −5 −10 −15 −20

LHC Higgs XS WG 2012

δbare

H l−¯ ν

δrec

H l−¯ ν

δbare

H l+ν

δrec

H l+ν

pT,V[GeV] δEW[%]

300 280 260 240 220 200 −5 −10 −15 −20

LHC Higgs XS WG 2012

δH ν¯

ν

δbare

H l+l−

δrec

H l+l−

pT,V[GeV] δEW[%]

300 280 260 240 220 200 −5 −10 −15 −20

LHC Higgs XS WG 2012

different lepton–photon recombination: rec for electrons bare for muons

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 50

EW Corrections to Higgs Production – Alexander M¨ uck – p.22/ 24

EW corrections

←→

| |

⇐ ⇒

boosted no pT,H/V cuts

δbare

H l−¯ ν

δrec

H l−¯ ν

δbare

H l+ν

δrec

H l+ν

yH δEW[%]

2 1 −1 −2 −5 −10 −15 −20

LHC Higgs XS WG 2012

δbare

H l−¯ ν

δrec

H l−¯ ν

δbare

H l+ν

δrec

H l+ν

yH δEW[%]

2 1 −1 −2 −5 −10 −15 −20

LHC Higgs XS WG 2012

larger EW corrections for boosted Higgs up to −15% for WH

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 51

EW Corrections to Higgs Production – Alexander M¨ uck – p.22/ 24

EW corrections

←→

| |

⇐ ⇒

boosted no pT,H/V cuts

δbare

H l−¯ ν

δrec

H l−¯ ν

δbare

H l+ν

δrec

H l+ν

yH δEW[%]

2 1 −1 −2 −5 −10 −15 −20

LHC Higgs XS WG 2012

δbare

H l−¯ ν

δrec

H l−¯ ν

δbare

H l+ν

δrec

H l+ν

yH δEW[%]

2 1 −1 −2 −5 −10 −15 −20

LHC Higgs XS WG 2012

larger EW corrections for boosted Higgs up to −15% for WH uncertainties (for differential analysis):

scale: 2% PDF: 5% missing higher orders (e.g. gg → V H): 1% (7%) for WH (ZH)

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 52

EW Corrections to Higgs Production – Alexander M¨ uck – p.23/ 24

Higgs Decays

←→

| |

⇐ ⇒

[GeV]

H

M 100 200 300 1000 Branching ratios

  • 3

10

  • 2

10

  • 1

10 1 500 b b τ τ c c t t gg γ γ γ Z WW ZZ

LHC HIGGS XS WG 2010

NLO EW corrections to Higgs boson decays: H → f ¯ f

Bardin, Vilensky, Khristova [Sov.J.Nucl.Phys. 53 (1991) 152] Dabelstein, Hollik [Z.Phys. C53 (1992) 507] Kniehl [Nucl.Phys. B376 (1992) 3]

H → γγ

Passarino, Sturm, Uccirati [arXiv:0707.1401]

H → gg

Actis, Passarino, Sturm, Uccirati [arXiv:0809.1301] LHC Higgs Cross Section Working Group [arXiv:1101.0593]

all included in HDECAY

(together with QCD corrections)

Djouadi, Kalinowski, Spira [hep-ph/9704448]

EW Corrections to Higgs Production – p. 0/ 24

slide-53
SLIDE 53

EW Corrections to Higgs Production – Alexander M¨ uck – p.23/ 24

Higgs Decays

←→

| |

⇐ ⇒

[GeV]

H

M 100 200 300 1000 Branching ratios

  • 3

10

  • 2

10

  • 1

10 1 500 b b τ τ c c t t gg γ γ γ Z WW ZZ

LHC HIGGS XS WG 2010

NLO EW corrections to Higgs boson decays: H → f ¯ f

Bardin, Vilensky, Khristova [Sov.J.Nucl.Phys. 53 (1991) 152] Dabelstein, Hollik [Z.Phys. C53 (1992) 507] Kniehl [Nucl.Phys. B376 (1992) 3]

H → γγ

Passarino, Sturm, Uccirati [arXiv:0707.1401]

H → gg

Actis, Passarino, Sturm, Uccirati [arXiv:0809.1301]

H → WW/ZZ → 4f

for off-shell/decaying W/Z bosons

Bredenstein, Denner, Dittmaier, Weber [hep-ph/0611234]

EW Corrections to Higgs Production – p. 0/ 24

slide-54
SLIDE 54

EW Corrections to Higgs Production – Alexander M¨ uck – p.23/ 24

Higgs Decays

←→

| |

⇐ ⇒

[GeV]

H

M 100 200 300 1000 Branching ratios

  • 3

10

  • 2

10

  • 1

10 1 500 b b τ τ c c t t gg γ γ γ Z WW ZZ

LHC HIGGS XS WG 2010

NLO EW corrections to Higgs boson decays: H → f ¯ f

Bardin, Vilensky, Khristova [Sov.J.Nucl.Phys. 53 (1991) 152] Dabelstein, Hollik [Z.Phys. C53 (1992) 507] Kniehl [Nucl.Phys. B376 (1992) 3]

H → γγ

Passarino, Sturm, Uccirati [arXiv:0707.1401]

H → gg

Actis, Passarino, Sturm, Uccirati [arXiv:0809.1301]

H → WW/ZZ → 4f

⇒ Prophecy4f MC generator

Bredenstein, Denner, Dittmaier, AM, Weber [http://omnibus.uni-freiburg.de/∼sd565/programs/prophecy4f/prophecy4f.html]

EW Corrections to Higgs Production – p. 0/ 24

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SLIDE 55

EW Corrections to Higgs Production – Alexander M¨ uck – p.24/ 24

Summary

←→

| |

⇐ ⇒

Discovery of a 125 GeV boson Is it the SM Higgs?

⇒ search for deviations from the SM ⇒ precision predictions most important (joint effort: Higgs cross section working group)

EW corrections:

available for major channels sizeable: 10% level included at inclusive level

  • ngoing efforts for differential analysis

EW Corrections to Higgs Production – p. 24/ 24

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SLIDE 56

EW Corrections to Higgs Production – Alexander M¨ uck – p.25/ 24

←→

| |

⇐ ⇒

Back-up slides

EW Corrections to Higgs Production – p. 24/ 24

slide-57
SLIDE 57

EW Corrections to Higgs Production – Alexander M¨ uck – p.26/ 24

Resonances

←→

| |

⇐ ⇒

problem:

1 p2−M2 ?

→

1 p2−M2+iMΓ

solution: complex mass scheme

Denner, Dittmaier, Roth, Wieders [hep-ph/0505042]

use complex W and Z masses everywhere by means of complex renormalization: M 2

V,0 = µ2 V + δµ2 V

with: M 2

V,0 = bare mass (V = W, Z)

µ2

V = ren. complex mass

δµ2

V = complex counterterm

⇒ complex s2

W = 1 − µ2 W/µ2 Z

loop-integrals for complex masses needed unitarity-violating beyond NLO accuracy gauge invariant valid everywhere in phase space

EW Corrections to Higgs Production – p. 24/ 24

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SLIDE 58

EW Corrections to Higgs Production – Alexander M¨ uck – p.27/ 24

Distributions

←→

| |

⇐ ⇒

example: rapidity separation (leading pT jets)

Figy, Oleari, Zeppenfeld [hep-ph/0306109]

⇒ no uniform K-Factor

EW Corrections to Higgs Production – p. 24/ 24

slide-59
SLIDE 59

EW Corrections to Higgs Production – Alexander M¨ uck – p.28/ 24

inclusive ⇔ VBF cuts

←→

| |

⇐ ⇒ relative NLO corrections for VBF:

Ciccolini,Denner,Dittmaier [arXiv:0710.4749]

EW, cuts EW, no cuts QCD, cuts QCD, no cuts pp → Hjj + X MH [GeV] δ [%]

700 600 500 400 300 200 100 10 5 −5 −10

cuts ⇔ no cuts: large difference for NLO QCD

however in this plot: s-channel included (large, positive correction) MRSTQED2004 PDF at LO/NLO

Tuned comparison in 2007:

LH Higgs working group [arXiv:0803.1154] without cuts (MH = 120 GeV) σVBFNLO

LO

= 4227.1(1) fb σVBFNLO

NLO

= 4414.8(2) fb

→ NLO QCD corrections: 4.4%

with cuts (MH = 120 GeV) σVBFNLO

LO

= 1686.90(5) fb σVBFNLO

NLO

= 1728.8(2) fb

→ NLO QCD corrections: 2.5%

EW Corrections to Higgs Production – p. 24/ 24