Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh...

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Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR, Mumbai) 7/29/2010 1 India-CMS meeting, BARC, Mumbai

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Page 1: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Study of L1 and HLT efficiency in VBTF

Monika Jindal (Panjab University, Chandigarh)

Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR, Mumbai)

7/29/2010 1India-CMS meeting, BARC, Mumbai

Page 2: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Introduction

Joined the Muon online trigger efficiency group in VBTF to contribute in the efficiency measurements of L1 and HLT trigger paths. In April/May various subgroups were made to work actively and efficiently for ICHEP.

CMS PAS EWK-10-002 has been published on EWK studies done by all VBTF subgroups collectively. The details of all the studies have been documented in CMS AN AN-10-116. The efforts of all the groups paid and CMS showed the results with 200 nb-1 in ICHEP .

During this ICHEP season, got a very good chance to explore myself with real data. It was good experience to share the excitement of real data analysis.

During last two months, performed the analysis with new data in many iterations to update the results with as much data as possible. Finally, the got the final numbers for trigger efficiency of “HLT_Mu9” and its level-1 seed “L1SingleMu7” with the full data at 200 nb-1 .

7/29/2010 India-CMS meeting, BARC, Mumbai 2

Page 3: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

CMS Trigger System CMS trigger system consists of two physical levels: Level-1 trigger (L1) hardware based and a High Level trigger (HLT) which is implemented in software.

The first step is the Level-1 trigger which receives data at full LHC bunch crossing rate of 40 MHz and output rate is limited by CMS DAQ to 100 KHz.

Second step in the CMS trigger chain is the HLT. It is designed to reduce the Level-1 output rate of 100 KHz to O(100) Hz. - The trigger paths are connected as: L3 L1 Input from L2 seeds Hardware based, uses information from DT, CSC Output L2 seeds which is a state vector (pos, dir and pt) and RPC Cleaning to remove tracks with Global Muon Trigger high number of shared hits Combines DT, CSC, RPC and Calorimeter Takes each L1 seed Final output four best seeds L2 7/29/2010 3India-CMS meeting, BARC, Mumbai

Page 4: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Two methods used to measure the L1 and HLT efficiency :

Using the four vector “hltTriggerSummaryAOD”. It returns the level-3 filtered object and no intermediate path. For example: for HLT_Mu9:

- L1 filtered object is : hltL1singleMu7L1Filtered7 which requires L1 muon with pt> =7.0 and quality >3.0 - L2 filtered object is: hltSingleMu9L2Filtered7 which requires L2 muon with pt>=7.0 - L3 filtered object is: hltSingleMu9L3Filtered9 which requires L3 muon with pt > 9.0

- hltTriggerSummaryAOD returns only the “hltSingleMu9L3Filtered9” object. So muons are matched with the final triggered object in this method.

Second method is “HLTDebug”

- In this method, first of all looked , if there is atleast one L1 muon matched with a muon in a given dR. - For the matched L1 muon, a search for L2 seed is done. - Then looked for if there is any L3 muon exits for the matched L2 seed.

7/29/2010 4India-CMS meeting, BARC, Mumbai

Page 5: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Data :

Estimated the trigger efficiencies using data driven methods. For the purpose, used the JetMET andTau triggered samples. In JetMET and Tau triggered samples, the events are required to pass the various Jet, MET and tau triggers.

Muon trigger efficiencies , then estimated from these sample which are forced to pass the Jet MET and Tau triggers leads to unbiased results. 1. /MinimumBias/ewk-Commissioning10-SD_JetMETTau-Jun14thSkim_v1-EWK_HighPtMuSkim-v1- 262fa66c8fc0da925698a868d3d7b3dd-EWKHighPtMuSkim/USER -Run Range: 132440-135735 , Lumi:~8.03nb-1

2./JetMETTau/ewk-Run2010A-Jun14thReReco_v2-EWK_HighPtMuSkim-v1- 262fa66c8fc0da925698a868d3d7b3dd-EWKHighPtMuSkim/USER -Run Range :136066-137028 , Lumi : ~ 5 nb-1

Above samples are skimmed by EWK group. Skimming conditions are: - pt > 15.0 && muon should be (isGlobal || is Tracker) - |innerTrack().dxy() |<1.0

7/29/2010 5India-CMS meeting, BARC, Mumbai

Page 6: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Further on data

3. /JetMETTau/Run2010A-PromptReco-v4/RECO Run Range: 137437-140180, Lumi: ~ 188.84 nb-1

- Skimmed the PromptRecov4 sample using the official EWK Skim file to merge with first two samples. Total integrated luminosity for the Data (sample 1+2+3) analyzed ~ 201.78 nb-1 (till July 19 th!)

Monte-Carlo Samples :

Skimmed the MC with JetMETTau trigger paths and EWK Skim paths to compare with Data.

Data Sample Cross-Section (pb)

Filter Efficiency

/WplusToMuNu-CTEQ66-powheg/Summer10-START36_V9_S09-v1/GEN-SIM-RECO

5553 1.

/WminusToMuNu-CTEQ66-powheg/Summer10-START36_V9_S09-v1/GEN-SIM-RECO

3791 1.

/InclusiveMu15/Summer10-START36_V9_S09-v1/GEN-SIM-RECO2.969e8 2.684e-4

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Event selection : - There should not be any beam halo. This condition is fulfilled by the condition on the given L1 technical trigger bits. - NOT (36 OR 37 OR 38 OR 39) - Scraping Veto to reject the beam background - Requires >=25% of high purity tracks.

- Event should pass the “GoodVertex Filter “ which requires : - there should not be any fake vertex and minimum no of tracks in the good vertex > 4 and starting point of the vertex should be with in 20 cm of the interaction point.

- Atleast one muon of any kind. - It can be global || tracker || standalone

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All the above muon Id cuts along with Isolation are applied on W+ and W- samples.

In case of QCD, the main contribution is from muons coming from decays in flight of heavy flavours which are not isolated, so no isolation is applied to have sufficient statistics

Motive to use QCD sample is to have large statistics.

7/29/2010 8India-CMS meeting, BARC, Mumbai

Muon quality cuts: (VBTF Wmunu baseline selection) - pt > 15 GeV && fabs(eta)<2.1 - numberOfValidPixelHits > 0. and numberOfTrakcerHits > 10. - absolute transverse impact parameter < 0.2 cm - normalized chi2 <10. and numberOfValidMuonHits > 0. && No of muon stations > 1 - Relative combined isolation variable : (trackerIso+ecalIso+hcalIso/Muonpt ) < 0.15 in a cone of radius 0.3

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Analysis WorkFlow: Propagation of Global muons : - Propagated the tracker track of muon to second muon station MB2/ME2 using stepping helix propagator. (including the package MuonAnalyzer/MuonAssociators.) - Checked if propagation is done successfully.

Matching global muons to L1 muons: - L1 particles are accessed using “l1extraParticle” module. - L1 muon with pt> = 7.0 and quality > 3.0 tagged as good L1 muon.

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DeltaR distribution between nearest L1 muon and global muon.

- Matched the global muons with the selected good L1 muon using dR. - Matching criteria is dR < 0.3

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Transverse momentum and eta distribution of global muons after matching with L1 muons MC is normalized to Data. Both are good agreement in low pt region, but there is little disagreement in high pt region. The disagreement will be studied in detail with high statistics.

7/29/2010 10India-CMS meeting, BARC, Mumbai

Page 11: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

L1SingleMu7 efficiency is defined as :

ε (L1SingleMu7) = Number of global muons matching to good L1 muon in dR < 0.3 /Number of global muons propagated after passing all the quality cuts

HLT_Mu9 efficiency is defined as:

- Only global muons matching to L1 muons are matched to “hltSingleMu9L3Filtered9” (filter path for HLT_Mu9)

- Matching criteria is : dR < 0.5 |dpt/pt| < 10. [(pt(global muon) – pt(L3 muon))/pt (L3 muon)]

ε (HLT_Mu9) = Number of global muons matching to “hltSingleMu9L3Filtered9 ” object / Number of global muons matching to good L1 muon in dR < 0.3

Efficiency of HLT_Mu9 is HLT w.r.t L1 i.e efficiency of L1SingleMu7 is not involved in the definition of HLT_Mu9.

7/29/201011India-CMS meeting, BARC, Mumbai

Page 12: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

L1SingleMu7 efficiency (without Isolation)

Low efficiency in L1 is due to timing synchronization problem reported by experts.

7/29/2010 12India-CMS meeting, BARC, Mumbai

Page 13: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

HLT_Mu9 efficiency (without Isolation)

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Page 14: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Efficiency |η|><0.9 0.9<|η|<1.2

|η|>1.2 Overall (%)

Data L1 0.9413+-0.0039

0.8128+-0.0126

0.9061+-0.0061

0.9118+-0.0033

HLT 0.9744+-0.0026 0.8638+-0.0123

0.9025+-0.0064 0.9375+-0.0029

MC L1 0.977+-0.0002

0.928+-0.0004 0.9469+-0.0002

0.9599+-0.0001

HLT 0.9687+-0.0001 0.9196+-0.0004 0.9428+-0.0002

0.9501+-0.0002

L1 and HLT efficiencies without Isolation (fit results) L1 efficiency in overall and three split eta regions.

Efficiency in quite low in 0.9-1.2 eta region. Checked the efficiency of the overlap region in two split parts : 0.9-1.05 and 1.05-1.2. (Next slide)

7/29/2010 14India-CMS meeting, BARC, Mumbai

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Split overlap region in two parts : - Efficiency is low in 1.05<|eta|<1.2 region. Techincal details are not known.

7/29/2010 15India-CMS meeting, BARC, Mumbai

Page 16: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

L1SingleMu7 efficiency (with Isolation)

Low efficiency in L1 is due to timing synchronization problem reported by experts.

7/29/2010 16India-CMS meeting, BARC, Mumbai

Page 17: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

HLT_Mu9 efficiency (with Isolation)

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Page 18: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Efficiency

|η|><0.9 0.9<|η|<1.2

|η|>1.2 Overall (%)

Data L1 0.9228+-0.0291

0.7465+-0.0783

0.9318+-0.0248

0.9057+-0.0185

HLT 1+-0.036 0.8869+-0.0784

0.8908+-0.0339 0.9426+-0.0165

(W+) L1 0.9753+-0.0013

0.9355+-0.0031 0.9531+-0.0015

0.9601+-0.0009

HLT 0.9831+-0.0009 0.9487+-0.0028 0.958+-0.0015

0.9679+-0.0008

(W-) L1 0.977+-0.0010 0.928+-0.0031 0.9589+-0.0015 0.963+-0.0009

HLT 0.9819+-0.0009 0.9393+-0.0031 0.9534+-0.0016 0.965+-0.0008

L1 and HLT efficiencies with Isolation (fit results)

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Page 19: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Efficiency numbers weighted by integrated luminosity of 200 nb -1

Sample Over All |eta|<0.9 0.9<|eta<1.2 |eta|>1.2

Data (with Iso) 86.16+-2.66 93.47+-6.82 65.02+-10.28 83.00+-4.94

Data (without Isolation)

85.61+-0.58 91.85+-0.59 71.15+-1.87 81.73+-1.01

Numbers represents the overall efficiency L1*HLT

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Page 20: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Conclusions

Main issuse for the inefficiency observed in L1 is the problem in timing synchronization. Experts are working on this issue.

Inefficiency in HLT is also being investigated. It can be due to the problem in L2 muon parameters or L3 seeding. Need HLTDebug content to investigate this issue. Samples with HLTdebug are not still available.

Plans

Main focus is on Drell-Yan spectrum study using the real data.

To study the various isolation variables in order to find out the suitable isolation variable for Drell-Yan. Done a preliminary work in this direction.

To study the UE event activity in Drell-Yan events.

7/29/2010 20India-CMS meeting, BARC, Mumbai

Page 21: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Back-up

7/29/2010 21India-CMS meeting, BARC, Mumbai

Page 22: Study of L1 and HLT efficiency in VBTF Monika Jindal (Panjab University, Chandigarh) Jasbir Singh (panjab University, Chandigarh), Kajari Mazumdar (TIFR,

Formula to calculate the Efficiency weighted wrt integrated Luminosity

- Consider two datasets : S1 and S2 corresponding to L1 and L2 integrated luminosity- Let e1 and e2 be the efficiencies of two samples S1 and S2 respectively.

- weight factor for sample S1 is w1 = L1/L1+L2- weight factor for sample S2 is w2 = L2/L1+L2

- Weighted Luminosity = w1* e1+ w2* e2

7/29/2010 22India-CMS meeting, BARC, Mumbai