In collaboration with: N. Greiner, S. Hche, M. Schnherr, V. Yundin - - PowerPoint PPT Presentation

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Dec 06, 2023 304 likes •583 views

Gionata Luisoni luisonig@mpp.mpg.de Max Planck Institute for Physics Munich In collaboration with: N. Greiner, S. Hche, M. Schnherr, V. Yundin and J. Winter 09/12/2014 Higgs + Jets WS, Durham H+jets in gluon-gluon fusion Dominant

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Gionata Luisoni luisonig@mpp.mpg.de Max Planck Institute for Physics Munich

In collaboration with:

  • N. Greiner, S. Höche, M. Schönherr, V. Yundin and J. Winter

09/12/2014 Higgs + Jets WS, Durham

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SLIDE 2
  • G. Luisoni

H+jets in gluon-gluon fusion

 Dominant channel of Higgs production  Large background makes it a prohibitive channel to directly study the

Higgs boson

 Nonetheless precise knowledge of GGF-channel is crucial:

 When applying vetoes to jets H+jets cross section needed to estimate

untertainties in efficiencies

 When studying VBF production channel Estimate contamination in VBF sample of

events coming from gluon-gluon fusion channel

H+2j sample can describe further radiation only at LO

09/12/2014 Higgs + Jets WS, Durham

[F. Krauss, M. Schönherr]

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SLIDE 3
  • G. Luisoni

H+jets in gluon-gluon fusion

 Recent ATLAS measurement:

09/12/2014 Higgs + Jets WS, Durham

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  • G. Luisoni

NLO Results

09/12/2014 Higgs + Jets WS, Durham

 Ingredients for a full NLO calculation:

 Virtual corrections  Tree amplitude  Subtraction scheme  Phase space integral

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SLIDE 5
  • G. Luisoni

Higher rank loop integrals

 For any 1-loop amplitude

Rank: = # powers of loop momentum in numerator

 in SM with renormalizable gauges:  in SM with effective Hgg vertex or ADD models:

09/12/2014 Higgs + Jets WS, Durham

Adapt reduction programs Samurai, Ninja and Golem95C to deal with higher rank loop integrals

[Mastrolia, Mirabella, Peraro; van Deurzen, Mastrolia] [Guillet, Heinrich, von Soden-Fraunhofen]

NEW

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  • G. Luisoni

H+jets: virtual corrections

H+0 jets

Processes

# Diagrams # Groups

H+1 jets H+2 jets H+3 jets

1 1 14 3 32 3 62 64 179 651 48 6 8 12 12 926 467 868 2519 9325 13179 32 44 60 60 < 1 ms 3 ms 7 ms 9 ms 15 ms 56 ms 68 ms 157 ms 999 ms 8‘960 ms 309 ms

# Helicities Timing (col.+hel. summed) 09/12/2014 Higgs + Jets WS, Durham

1 4 8 4 6 8 16 8 12 16 32

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  • G. Luisoni

H+jets in gluon-gluon fusion

H+3 jets

 Calculation setup so far:

 B amplitudes: Sherpa (Amegic)  V amplitudes: GoSam  IRS amplitudes: MG4/MadDipole

 Checks:

 Gauge invariance of virtual amplitudes  a-independence of IRS contribution  H+2j comparison and B comparison for combination

09/12/2014 Higgs + Jets WS, Durham

PS integration: Sherpa (BLHA) PS integration: MadEvent

Full NLO

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  • G. Luisoni

H+2 jets

 Computed using GoSam + Sherpa  Possibility to test the framework by comparing to existing results/codes

  • -> agreement with MCFM (v6.4)

 Calculation setup: LHC 8 TeV

anti-kt: R=0.5 pT>20 GeV |h| < 4.0 PDFs: cteq6L1 @ LO cteq6mE @ NLO scales:

09/12/2014 Higgs + Jets WS, Durham

[van Deurzen, Greiner, G.L., Mastrolia, Mirabella, Ossola, Peraro, von Soden-Fraunhofen, Tramontano]

[Campbell, Ellis, Williams]

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SLIDE 9
  • G. Luisoni

First H+3 jets results

 Computed using GoSam + Sherpa + MadGraph4/MadDipole/MadEvent

 Calculation setup: LHC 8 TeV with ATLAS cuts

anti-kt: R=0.4 pT>30 GeV |h| < 4.4 PDFs: cteq6L1 @ LO CT10nlo @ NLO scales:

09/12/2014 Higgs + Jets WS, Durham

[Cullen, van Deurzen, Greiner, Huston, G.L., Mastrolia, Mirabella, Ossola, Peraro,Tramontano, Yundin, Winter; 1307.4737, LH2013]

:

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SLIDE 10
  • G. Luisoni

H+jets in gluon-gluon fusion

H+3 jets

 Calculation setup so far:

 B amplitudes: Sherpa (Amegic)  V amplitudes: GoSam  IRS amplitudes: MG4/MadDipole

 New ongoing calculation:

 B amplitudes: Sherpa (Comix)  V amplitudes: GoSam  IRS amplitudes: Sherpa (Comix)

09/12/2014 Higgs + Jets WS, Durham

PS integration: Sherpa (BLHA) PS integration: MadEvent

Full NLO

PS integration: Sherpa (BLHA)

Full NLO + merging + shower NLO Events as NTuples

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  • G. Luisoni

Ntuples for H+2jets and H+3jets

 At present ~ 1.3T of Ntuples files:

 H+2 jets:

 50 B and I files of 5 Milion events each  200 V files of 100000 events each  100 RS files of 5 Milion events each

 H+3 jets:

 50 B and I files of 5 Milion events each  300 V files of 25000 events each  500 RS files of 5 Milion events each

 Advantages:

 Flexibility / portability / moderately fast to reanalyse

09/12/2014 Higgs + Jets WS, Durham

[LH2010; 1310.7439]

Storage Space: ~ 317 G Storage Space: ~ 1 T

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SLIDE 12
  • G. Luisoni

Calculation Setup

 So far results for LHC at 8 TeV:

anti-kt: R=0.4 pT>30 GeV |h| < 4.4 PDFs: CT10nlo

 Scales:

 Default: (A)  Variation:

 (B):  (C):  (D):

09/12/2014 Higgs + Jets WS, Durham

[Greiner, Höche, G.L., Schönherr, Yundin, Winter]

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  • G. Luisoni

Inclusive cross section

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

Results are in pb:

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  • G. Luisoni

Dependence on scale choice

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

LHC 8 TeV

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  • G. Luisoni

Jet radius dependence

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY  Ntuples for R=0.1, … , 1.0  At NLO dependence on jet radius stabilizes

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  • G. Luisoni

Higgs pseudorapidity

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

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  • G. Luisoni

Higgs rapidity

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

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  • G. Luisoni

Higgs transverse momentum

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

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SLIDE 19
  • G. Luisoni

Dependence on scale choice

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

(A) (C) (B) (D)

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  • G. Luisoni

Jet radius dependence

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

R=0.2 R=0.4 R=0.6 R=0.8 R=1.0

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  • G. Luisoni

Jets rapidities

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

H+2 jets H+3 jets

 1st jet 2nd jet  3rd jet

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  • G. Luisoni

Jets transverse momenta

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

H+2 jets H+3 jets

 1st jet 2nd jet  3rd jet

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SLIDE 23
  • G. Luisoni

Jets transverse momenta

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

 r3/2: strong dependence in Ptj distributions (50% at 100 GeV)  r3/2: different behaviour for hardest and 2nd hardest jet than for

3rd hardest one

 1st jet 2nd jet  3rd jet

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  • G. Luisoni

Results with VBF-type cuts

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

 Only about 7%

  • f events from

Ntuples pass VBF cuts

 R-dependence

has only small effect on efficiency, whereas pt-cut has a much larger one

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  • G. Luisoni

Hjj transverse momentum

09/12/2014 Higgs + Jets WS, Durham

PRELIMINARY

VBF-type cuts GGF-type cuts

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  • G. Luisoni

Conclusions & Outlook

 Preliminary new H+3 jets at NLO in ggf

 Computed using GoSam+Sherpa  ~1.3 Tb of Ntuples availables  Scale / radius dependence  Momenta and rapidities of Higgs and jets

  • Work in progress
  • Finish validation
  • More accurate study of impact of VBF-type cuts
  • Correlation observables / scale choices / PDFs
  • Matching to shower and merging of different multiplicities

09/12/2014 Higgs + Jets WS, Durham