Jet-Gap-Jet analysis software page

1. MC sample:

You can find in /castor/cern.ch/user/a/aproskur/mc

  • hardcol_*.root - HARDCOL trees
  • herwig_*.root - HERWIG trees (jgj events also)
  • pythia_*.root - PYTHIA dijet events

All was generated with pT > 40. GeV, FastSim 2.2.6 (L2L3Corrections _Summer09)

2. Jet-gap-jet analysis

Analysis Code

Distributions

3. Jet Performance

We present the study that was performed to test if the relative (L2) and the absolute (L3) calibration constants work for the jets in jet-gap-jet events.

Analysis Code

Analysis code of the performances of jet reconstruction with CMSSW_2_2_6 in HARDCOL[1] samples with 5.0M jet-gap-jet events using L2L3Corrections _Summer08:

It produces the distributions:

  • pTRecoJet / pTGenJet
  • | ηRecoJet | - | ηGenJet |
  • ΦRecoJet - ΦGenJet
  • ΔR

Plots macros:

macro_response_2.C: Produce the jet pT response for each pTGenJet bin X | η | bin (4x16 plots) and fitted by a Gaussian.

macro_mean_pt_SC5_KT4.C: Produce <response> for vs pTGenJet for SC5 and KT4.

macro_mean_eta_SC5_KT4.C: Produce <response> vs η for SC5 and KT4.

macro_resolution_pt_SC5_KT4.C: Produces pT resolution vs pTGenJet for SC5 and KT4.

macro_resolution_eta_SC5_KT4.C: Produces pT resolution vs | η | for SC5 and KT4.

macro_etaresolution_SC5_KT4.C: Produces η resolution vs pTGenJet for SC5 and KT4.

macro_phiresolution_SC5_KT4.C: Produces Φ resolution vs pTGenJet for SC5 and KT4.

macro_jeteff_SC5_KT4.C: Produces the Jet Matching Efficiency vs pT and η for SC5 and KT4.

Jet Energy Calibration

The Jet Response, defined as the ratio between the corrected pT of reconstructed jet (RecoJet) and pT of the corresponding particle-level jet (GenJet).

It was measured as function of η and pTRecoJet as suggested by Konstantinos Kousouris. This is a standard JetMET group procedure.

The MC data were split into 16 pT bins:

  • pTGenJet = {20., 25., 30., 35., 40., 45., 50., 55., 60., 65., 70., 75., 80., 85., 90., 95., 100.} GeV

and the range of pseudo-rapidity | η | < 5 was divided into 4 regions:

  • Barrel: 0.0 < | η | ≤ 1.4
  • Endcaps: 1.4 < | η | ≤ 2.6
  • Transtion regions between endcaps and forward: 2.6 < | η | ≤ 3.2
  • Forward: 3.2 < | η | ≤ 4.7

For each of the resulting 4X16 bins the response distribution was obtained using only the 2-leading jets (2 GenJets with the highest pTGenJet).

Both RecoJet and GenJet were reconstructed with the SISCone (R=0.5) and KT (D=0.4) algorithm.

The corrected jet response peaks near 1, indicating that the applied corrections are working. The histograms of the corrected jet response have been fitted with a Gaussian function in the interval 1.5σ centered around the mean.

Matching

The matching with the 2-leading GenJets was done by minimising the distance

and requiring R < 0.25; jet pairs not satisfying this criterion were rejected.

Jet Response and Resolution

Jet pT response were fitted with Gaussian function in the interval 1.5σ centered around the mean. The mean and σ parameters of the Gaussian fits were extracted and used as data points to determine the jet energy resolution curve as a function ofpTGenJet. Using the histograms of the jet response, the fractional jet pT resolution was calculated as function of pTGenJet.

The resolution curves were then fitted with a function of the following form:

Distributions

Jet Response

Jet pT response for SISCone (R=0.5) and KT (D=0.4) jet algorithms. The Gaussian fits to the 1.5σ centered around the mean.

Jet Response and Resolution;

Jet pT response as a function of pTGenJet and | η | for SISCone (R=0.5) and KT (D=0.4) jet algorithms.

Jet pT resolution as a function of pTGenJet.

Jet η resolution as a function of pTGenJet.

Jet Φ resolution as a function of pTGenJet.

Jet Matching Efficiency

Jet matching efficiency vs pTGenJet and η

Matched GenJet pT which pass in HLT_DiJetAve30

Presentations

References

[1] R. Enberg, G. Ingelman, L. Motyka, Phys.Lett. B524 (2002) 273-282.
[2]

Contact

Responsible: SheilaMaraSilvaDoAmaral

Topic attachments
I Attachment History Action Size Date Who Comment
C source code filec JECanalysisKT4_1.C r1 manage 13.4 K 2009-10-02 - 21:06 UnknownUser  
Header fileh JECanalysisKT4_1.h r1 manage 27.3 K 2009-10-02 - 21:06 UnknownUser  
C source code filec JECanalysisSC5_1.C r2 r1 manage 13.4 K 2009-10-02 - 21:06 UnknownUser  
Header fileh JECanalysisSC5_1.h r1 manage 27.3 K 2009-10-02 - 21:06 UnknownUser  
PNGpng deltar.png r1 manage 158.0 K 2009-10-02 - 21:50 UnknownUser  
PDFpdf etaresolution_SC5_KT4.pdf r1 manage 381.0 K 2009-10-02 - 21:29 UnknownUser  
PNGpng fitsigma.png r1 manage 526.4 K 2009-10-02 - 21:20 UnknownUser  
PDFpdf hltdijetave30.pdf r1 manage 52.4 K 2009-10-02 - 21:43 UnknownUser  
PDFpdf jec2-2.pdf r1 manage 4437.5 K 2009-10-02 - 21:32 UnknownUser  
PDFpdf jec2-3.pdf r2 r1 manage 4461.5 K 2009-10-06 - 12:56 UnknownUser  
PDFpdf jec2-4.pdf r1 manage 4463.1 K 2009-10-07 - 17:18 UnknownUser  
PDFpdf jet_matching_efficiency.pdf r1 manage 51.8 K 2009-10-02 - 21:43 UnknownUser  
C source code filec macro_etaresolution_SC5_KT4.C r1 manage 6.7 K 2009-10-02 - 21:16 UnknownUser  
C source code filec macro_jeteff_SC5_KT4.C r1 manage 6.4 K 2009-10-02 - 21:17 UnknownUser  
C source code filec macro_mean_eta_SC5_KT4.C r1 manage 5.4 K 2009-10-02 - 21:15 UnknownUser  
C source code filec macro_mean_pt_SC5_KT4.C r1 manage 5.4 K 2009-10-02 - 21:15 UnknownUser  
C source code filec macro_phiresolution_SC5_KT4.C r1 manage 6.7 K 2009-10-02 - 21:16 UnknownUser  
C source code filec macro_resolution_pt_SC5_KT4.C r1 manage 8.2 K 2009-10-02 - 21:16 UnknownUser  
C source code filec macro_responseKT4_2.C r1 manage 3.3 K 2009-10-02 - 21:15 UnknownUser  
C source code filec macro_response_2.C r1 manage 3.3 K 2009-10-02 - 21:15 UnknownUser  
PDFpdf phiresolution_SC5_KT4.pdf r1 manage 382.3 K 2009-10-02 - 21:29 UnknownUser  
PDFpdf resolution_pt_SC5_KT4.pdf r1 manage 428.4 K 2009-10-02 - 21:28 UnknownUser  
PNGpng response.png r1 manage 142.5 K 2009-10-02 - 21:53 UnknownUser  
PDFpdf responseKT4.pdf r1 manage 1587.7 K 2009-10-02 - 21:27 UnknownUser  
PDFpdf responseSC5.pdf r1 manage 1685.0 K 2009-10-02 - 21:26 UnknownUser  
PDFpdf responsemean_eta_SC5_KT4.pdf r1 manage 526.6 K 2009-10-02 - 21:28 UnknownUser  
PDFpdf responsemean_pt_SC5_KT4.pdf r1 manage 326.2 K 2009-10-02 - 21:27 UnknownUser  
PNGpng sigma.png r1 manage 178.4 K 2009-10-02 - 21:20 UnknownUser  
Edit | Attach | Watch | Print version | History: r8 < r7 < r6 < r5 < r4 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r8 - 2012-01-02 - DavidDEnterria
 
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    CMSPublic All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2019 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback