mc generators for cms
DESCRIPTION
MC Generators for CMS. Overview of the CMS MC Generator group: activities and tasks. Paolo Bartalini, University of Florida Filip Moortgat, ETH Zurich. Mini-Workshop on Early CMS Physics , Fermilab, June 8 2007. MC Generators vs CMS organization. - PowerPoint PPT PresentationTRANSCRIPT
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Paolo Bartalini, University of FloridaFilip Moortgat, ETH Zurich
MC Generators for CMSMC Generators for CMS
Overview of the CMS MC Generator group:activities and tasks
Mini-Workshop on Early CMS Physics, Fermilab, June 8 2007
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MC Generators vs CMS organizationMC Generators vs CMS organization
• New CMS management -> CMS Physics Groups recently re-organized. • The emphasis is on the early measurements and their impact on detector
commissioning/calibration activities• CMS MC Generator Tools (F. Moortgat, P. Bartalini)
• Implementing and maintaining generator interfaces in CMSSW• Organizing MC production requests -> Spring 2007, CSA07• Validating/comparing generators & related tools• MC tuning
• All this happens after two important 2006 milestones• The publication of the CMS Physics TDR
• Generator framework frozen to provide a stable reference -> sticking with the Fortran based CMKIN
• The CSA06 exercise• Emphasis on Computing issues (data transfer between Tiers etc.) -> Migration of the MC generators in CMSSW started-> MC Validation & Tuning activities not particularly relevant
As a consequence current relevant MC Tuning & Validation activities are still a bit ALPGEN & Pythia centric
Fundamental validation tests (Sanity Checks, Basic Conservation Properties) are of course also ongoing for all the other Monte Carlo generators (see next slides)
More information at https://twiki.cern.ch/twiki/bin/view/CMS/GeneratorMain
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Generators in CMSSW (1)Generators in CMSSW (1)
GeneratorInterface in CMSSW: Pythia6Interface +++ H. Naves, F. Moortgat Herwig6Interface +++ F. Stoeckli (including Jimmy) Pythia8Interface ++ M. Kirsanov Herwig++Interface + (expression of interest, Karlsruhe) SherpaInterface + (expression of interest, Karlsruhe) HydjetInterface ++ C. Mironov TopRexInterface ++ S. Slabospitsky MC@NLOInterface +++ F. Stoeckli ALPGENInterface ++ M. Pierini, M. Spiropulu MadGraphInterface +++ D. Kcira, M. Hansen (also works for Phantom and Helac) (S. Bolognesi, F.M.) CompHepInterface ++ S. Slabospitsky, D. Konstantinov EvtGenInterface + U. Langenegger, R. Covarelli
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Generators/Tools in CMSSW (2)Generators/Tools in CMSSW (2) Continued: ExHumeInterface +++ A.Vilela Pereira PomwigInterface +++ A.Vilela Pereira LHAPDF ++ H. Naves, F.M. CosmicMuonGenerator +++ P. Biallass BeamHaloGenerator ++ E. Perez ParticleGuns ++ J. Yarba MCFileReader ++ J. Weng NtupleConverter ++ J. Weng
More information https://twiki.cern.ch/twiki/bin/view/CMS/GeneratorTaskList
+++ = advanced++ = ongoing+ = resources identified
GENSER1 / GENSER2 Libraries are adopted, if available & no need to modify
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News in CMSSW_1_4_XNews in CMSSW_1_4_X
• new HepMC version from LCG (event record)• new HepPDT version from LCG (particle data table)• code reorganization: all generator interfaces and filters in “GeneratorInterface”
• Pythia version 6.409: includes (optional) new parton shower and underlying event model, SLHA interface and quarkonia production
• HERWIG/Jimmy included• MC@NLO included • LHAPDF included• Cosmic Muon Generator updated• Two dedicated diffractive generators included
• Run section will include cross section (2) and filter efficiency
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Spring07 statusSpring07 status
Spring07 GEN-SIM production with CMSSW_1_2_3 basically done.
~35 M events (~500 requests) done few late/special requests still ongoing
DIGI-RECO of these samples with CMSSW_1_3_1 is ~90% done:
Total: ~50M events processed / month
https://twiki.cern.ch/twiki/bin/view/CMS/GeneratorProduction2007
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Spring07 status (2)Spring07 status (2)
• for details about specific samples :
1) production status:
https://cmsdoc.cern.ch/cms/test/aprom/DBS/prodrequest/ProdRequest/getAllRequestsPage
2) data location: (! Use DBS-2 site!)
http://cmsdbs.cern.ch/DBS2_discovery/
All data will by default go to CERN/FNALYou can request the data to go to specific sites using Phedex: http://cmsdoc.cern.ch/cms/aprom/phedex/
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CSA07 planCSA07 plan
• CSA07 Production: 100M CSA07 “Standard Model” cocktail:
Min bias (20 Mevt)QCD jets (25 Mevt) and +jets (5 Mevt)Electrons/muons from b-decays (20 Mevt)Drell-Yan and Onia (10 Mevt)W/Z (plus jets) (15 Mevt)Top (5 Mevt)
• details (developing): see https://twiki.cern.ch/twiki/bin/view/CMS/GeneratorProduction2007CSA07
• Summer07 production: all signal samples and background samples missing in the above will be produced at the Tier-2’s
ALPGEN
PYTHIA
Will be produced with CMSSW_1_4_X (GEN+SIM) and CMSSW_1_5_X (DIGI+RECO)
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May mini workshopsMay mini workshops
Agenda MC Tuning workshop:
Recent activities: two mini-workshops in May:
May 14th: MC Tuning mini w/s May 21st: ALPGEN Generation mini w/s
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- To provide both Best and Error settings for- Hard process description- Hard process scale - PDF description - QCD radiation- Fragmentation of light and heavy quarks- Minimum Bias (including the variations in the
relative amount of diffractives etc.) - Underlying Event- Decays- Etc.
Some guidelines available in CMS Note 2005/013 (To be reviewed)
The MC Tuning Goals The MC Tuning Goals
See also talk of Rick Field, This Morning
Big Issue for “Predicting” at the LHC ==> Energy Dependency of the ParametersOften need to make compromises: no LO PDF Error Sets, etc.
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Relaxing the momentum sum rule: LO*Relaxing the momentum sum rule: LO*
LO* performs better than LO and NLO in both cases
[R. Thorne]
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PYTHIA 6.2 TunesPYTHIA 6.2 TunesParameter Tune DW Tune DWT ATLAS Tune QW Tune QWT Tune QK Tune QKT
PDF CTEQ5L CTEQ5L CTEQ5L CTEQ6.1 CTEQ6.1 CTEQ6.1 CTEQ6.1
MSTP(2) 1 1 1 1 1 1 1
MSTP(33) 0 0 0 0 1 1 1
PARP(31) 1.0 1.0 1.0 1.0 1.0 1.8 1.8
MSTP(81) 1 1 1 1 1 1 1
MSTP(82) 4 4 4 4 4 4 4
PARP(82) 1.9 GeV 1.9409 GeV 1.8 GeV 1.1 GeV 1.1237 GeV 1.9 GeV 1.9409 GeV
PARP(83) 0.5 0.5 0.5 0.5 0.5 0.5 0.5
PARP(84) 0.4 0.4 0.5 0.4 0.4 0.4 0.4
PARP(85) 1.0 1.0 0.33 1.0 1.0 1.0 1.0
PARP(86) 1.0 1.0 0.66 1.0 1.0 1.0 1.0
PARP(89) 1.8 TeV 1.96 TeV 1.0 TeV 1.8 TeV 1.96 TeV 1.8 TeV 1.96 TeV
PARP(90) 0.25 0.16 0.16 0.25 0.16 0.25 0.16
PARP(62) 1.25 1.25 1.0 1.25 1.25 1.25 1.25
PARP(64) 0.2 0.2 1.0 0.2 0.2 0.2 0.2
PARP(67) 2.5 2.5 1.0 2.5 2.5 2.5 2.5
MSTP(91) 1 1 1 1 1 1 1
PARP(91) 2.1 2.1 1.0 2.1 2.1 2.1 2.1
PARP(93) 15.0 15.0 5.0 15.0 15.0 15.0 15.0
Intrensic KT
ISR Parameter
UE Parameters
K-factor(Sjöstrand)
Use LO s with = 192 MeV!
[Rick Field]Now also D6 and D6T available (Tunes with CTEQ6L PDFs)
Two different solutions for the energy dependency of the PT cut-off in MI==> Define methodology to estimate some of the theoretical uncertainties
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1. How well can we predict the isolation cut efficiency using the current Monte Carlo generators?2. Can we calibrate the isolation cut efficiency using the experimental data themselves and, if yes, would the associated experimental systematicerrors be smaller than the Monte Carlo based theoretical uncertainties?
Isolation parameter is a sum of PT of tracks inside a cone dR(η,φ) = 0.3 (PT of considered tracks > 0.8 GeV)
5% uncertainty only in one cut
-3σ case (smaller PTcut-
off)-0σ case (default PTcut-
off)+3σ case (greater PTcut-
off)
Random cone direction: all the calculations for isolation observable done for uniformly distributed random directions in event instead of directions for 'real' muons.
2% relative uncertaintyw.r.t. Drell-Yan
[CMS Note 2006/033]
UE: Application to muon isolation in H4 search(suppression of tt and Zbb backgrounds)
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Quarkonia also prefers dampening...Quarkonia also prefers dampening...
Total Color octet Color-singlet
pT0=2.85 GeV nice agreement
CTEQ6L|y|<0.6
(/
)/
(/
)T
Br
Jd
dpnb
GeV
ψ
σ→
g[M.Bargiotti]
(/
)/
(/
)T
Br
Jd
dpnb
GeV
ψ
σ→
g
Phys. Rev. D71: 032001, 2005
CDF data
CTEQ6L|y|<0.6
disagreementdisagreementat low Pat low PTT
NRQCDPYTHIA
NRQCDPYTHIA
Regularization natural: gluon exchange in the t channel dσ/dPT2 ~ 1/ dPT
4
LHC Predictions:Let’s assume universality: same PT0 of MPI, same energy dependency!
[M.Bargiotti]
Total Color octet Color-singlet
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PYTHIA 8 vs. CDF for the J/ψ
Good agreementfor pT above 2 GeV/c
[C. Lourenco]
Similar but not “universal” for Y
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The candidates (charged particles) are created and used to define the observables at generator level
Results are summarized in terms of:+ charged spectra+ charged jet kinematics+ MB and UE observables
Validation of PythiaValidation of Pythia 6.2 6.2 vsvs 6.36.3 vsvs 6.46.4based on based on MBMB and and UEUE Analyses in Analyses in CMSSWCMSSW
CMSSW Package: AnalysisExamples/MinimumBiasUnderlyingEvent
[L. Fano’]
UE&MB@CMSUE&MB@CMS
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6.26.36.4
More soft charged in 6.4?
Minimum Bias: basic kine observables on charged tracks
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Minumum Bias: MB and UE observables
Softer charged spectrum more evident ?
6.26.36.4
In UE observables, charged are selected with PT>0.5
toward away
transverse
away
“Toward”
“Away”
“Transverse”“Transverse”
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central forward
no correlation
long range correlation
Pythia without MI -> no correlation
Pythia with MI:
Long range correlations, trigger enhancing differences in the central region
MPI Model effect on Long range correlations
Generator Level Studies with Pythia 6.409
[K.Borras](Thanks to P.Skands for making available PYTUNE)
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Simulation of forward protons What do we expect ?
Diffractive peak
pLeading protons
xL=P’/Pbeam
Fastest proton in the event
Universal numberSame for ep, ppNo surprise: vertex factorisation
[Grothe, Ruspa]
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Pythia wrong in shapeand normalisation outsidediffractive peak(approx factor 2-3)
xL=P’/Pbeam
Fastest proton in the event
Pythia approx OK in diffractive peak(after removing elasticcomponent, not therein HERA data)
Phojet slightly worse than Pythia [Grothe, Ruspa]
Simulation of forward protons What we find...
Re-weighting adopted
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Results of an automated PERL script which allows to run the same CMSSW job with all the versions of a MC generators available in GENSER
All charmonia processes (ISUB = 421-439) have been chosen. No cross-section reweigthing has been applied. Cross-sections are for all included subprocesses.Pythia version Events generated Total cross-section (mb)6_325 100000 1.130E+016_326 100000 1.130E+016_327 100000 1.130E+016_400 100000 1.130E+016_402 100000 1.130E+016_403 100000 1.130E+016_404 100000 1.130E+016_405 100000 1.130E+016_406 100000 1.370E+016_409 100000 1.370E+01The transition apparently happens when going from Pythia version 6_405 to version 6_406. Please find Pythia release notes under the following URL's:Pythia 6.3 : http://www.thep.lu.se/~torbjorn/pythia/pythia6327.updatePythia 6.4 : http://www.hepforge.org/downloads/Pythia6
Example of Automated Validation
[F. Bechtel]
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Other Examples of Automated Validation from LCG
http://lcgapp.cern.ch/project/simu/generator/genval.html
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ALPGEN mini workshopALPGEN mini workshop
I. Segoni
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ALPGEN processesALPGEN processes
ALPGEN production/validation for Spring07 ALPGEN production/validation for Spring07 productionproduction
Channel Comment
ttbar + Jets [Spiropulu, Chierici, Schmidt] Available
W + Jets [Segoni,Kasselmann] Available(2,5 Jets)
Ongoing(0,1,3,4,6 Jets)
Z +Jets [Feltzmann] Available
WW/WZ/ZZ + Jets [Karapostoli] Available
Triboson + Jets [Gascon-Shotkin] Production
W/Z bb +Jets [Chierici, Karapostoli]
Available, need finalization
NJets [Rutgers: Chuang et al.]
t + Jets Manpower identified*
N b + Jets NN
Work in close collaboration with the ALPGEN authors.New implementations often triggered by the CMS requests for example: matching for QQQ’Q’ to appear in v2.2x
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ALPGEN: ComputingALPGEN: Computing
G. Gomez-Ceballos,M. Klute,D. Evans,A. Fanfani
• cmsGen script has been written for ME generation (before cmsRun) https://twiki.cern.ch/twiki/bin/view/CMS/CmsGen https://twiki.cern.ch/twiki/bin/view/CMS/ProdAgentDevelopmentPlan
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ALPGEN: ALPGEN: W/Z+jets with VBF preselectionW/Z+jets with VBF preselection
iteration 1iteration 2iteration 3iteration 4~60 jobs eachnormalised to 1
iteration 1iteration 2iteration 3~240 jobs eachnormalised to 1
W+3jet W+4jet
iteration1 iteration2 iteration3 iteration1 iteration2 iteration3
efficiency: unw/Nevts
wgt/Nevts
unw/wgt
1.2 x 10-4
5.6 x 10-4
0.21
2.2 x 10-4
9.2 x 10-4
0.24
2.1 x 10-4
8.6 x 10-4
0.24
0.3 x 10-4
3.7 x 10-4
0.07
1.3 x 10-4
9.6 x 10-4
0.14
1.3 x 10-4
9.8 x 10-4
0.14
[Nikitenko, Greder, Takahashi]
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[Pierini, Spiropulu]
Goal: to Study the Tail of the Boson PT
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Future of MC Future of MC Tuning & Validation in CMSTuning & Validation in CMS
A more “inclusive” and “systematic” approach is needed
From basic sanity checks to physics validation for all the supported models
From local tuning/validation to global tuning/validation Convenient Frameworks need to be evaluated/adopted. Evaluation phase
- Vista - Rivet/JetWeb
Official visit of the PH Generators’ group to Fermilab - Thanks to S.Mrenna, P.McBride etc.
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Official visit of the PH Generators’ group to Fermilab Thanks to S.Mrenna, P.McBride etc.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Now collecting several expression of interest to contribute to the activities of the CMS Generator Group- Theory, Exp (from CDF, D0 etc.).- Don’t hesitate to contact us ! Tomorrow: MC Generators tutorial (Filip)
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BACKUPBACKUP
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CMS PH OrganigramCMS PH Organigram
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April 2007 MC Meetings (Phys. Days)April 2007 MC Meetings (Phys. Days)
Generator Meeting• HELAC - PHEGAS : automatic helicity amplitude calculation and
parton level generation (Costas Papadopoulos)• VBFNLO : NLO parton level MC for Vector Boson Fusion (Manuel
Baehr)• A simple root format for generator events (Oliver Oberst )
SUSY/BSM Meeting• SUSY-HIT and SDECAY status (Milada Muehlleitner)
B-Physics Meeting• EvtGen Interface Status Report (Roberto Covarelli)
QCD/TOP/EW Meeting• News from MC production (Ilaria Segoni)
Plenary• Vista@CMS: Physics Commissioning (Bruce Knuteson)
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MadGraph in CMSSW: Flow of EventsMadGraph in CMSSW: Flow of Events
MadGraph•Generate events•Output partons•LesHouches format
MadGraphInterface•Generate event•Populate event from input file usinguser routines from ME2pythia.f•Parton shower•Hadronization`
HEADER:. . .EVENTS:<event> 4 661 0.7533903E-01 0.9118800E+02 0.7818608E-02 0.1300000E+00 21 -1 0 0 502 503 0.00000000000E+00 0.00000000000E+00 0.72071194343E+03 0.72071194343E+03 0.00000000000E+00 0. -1. 21 -1 0 0 501 502 0.00000000000E+00 0.00000000000E+00 -0.14548493253E+03 0.14548493253E+03 0.00000000000E+00 0. 1. 6 1 1 2 501 0 -0.42290358713E+02 -0.12398540766E+03 -0.32583445893E+02 0.22046094144E+03 0.17430000000E+03 0. 1. -6 1 1 2 0 503 0.42290358713E+02 0.12398540766E+03 0.60781045680E+03 0.64573593453E+03 0.17430000000E+03 0. -1.</event>
•Les Houches format•Plain text file
Pool FileHepMCProduct
Package: GeneratorInterface/MadGraphInterfaceDorian Kcira et al.
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