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First Attempts: ABCD Method for background estimation of W→e ν

First Attempts: ABCD Method for background estimation of W→e ν. Shu Li, Yanwen Liu Together with Elisabeth Petit, Fabrice Hubaut , Pascal Pralavorio Center of Particle Physics and Technology, USTC &Center de Physique des Particules de Marseille,

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First Attempts: ABCD Method for background estimation of W→e ν

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  1. First Attempts:ABCD Method for background estimation of W→eν ShuLi, Yanwen Liu Together with Elisabeth Petit, FabriceHubaut, Pascal Pralavorio Center of Particle Physics and Technology, USTC &Center de Physique des Particules de Marseille, CNRS-IN2P3 / Université de la Méditerranée - Aix Marseille II

  2. Datasets in use • 7TeV Collision data used: (~14M evts) • L1CaloEM ESD: all of RunNumber 152166-153599 • L1Calo ESD: all of RunNumber 154810-155160 • MC Samples used: • mc09_7TeV.105802.JF17_pythia_jet_filter.merge.AOD.e505_s765_s767_r1302_r1306 (10M evts, serves as background with signal components excluded) • mc09_7TeV.105805.filtered_minbias6.merge.AOD.e530_s765_s767_r1302_r1306 (7M evts, signal sample)

  3. Basic Selection Criteria in use based on WZObservation fundamental requirements on Twiki: https://twiki.cern.ch/twiki/bin/view/AtlasProtected/WZObservation7TeV • PreSelections: • Event Level: • Ask for stable beam LumiBlock based on InterestingRunsTwiki: https://twiki.cern.ch/twiki/bin/view/AtlasProtected/InterestingRuns2010 • GRL used: (going to update with new egamma GRLs) • data10_7TeV.periodA.152166-153200_LBSUMM_DetStatus-v02-repro04-00_eg_standard_7TeV.xml • data10_7TeV.periodB.153565-155160_LBSUMM_DetStatus-v02-repro04-00_eg_standard_7TeV.xml • Good LumiBlock with Stable beams required for all runs • L1_EM2 trigger passed • Good Primary Vertex with ≥3 tracks • MET_cleaning implemented using JetCaloQuality Tool (https://twiki.cern.ch/twiki/bin/view/Sandbox/JetCaloQuality)

  4. Further PreSelections: • Object Level: • Fiducial Cuts applied using CheckOQ Macro(Version4, not the latest) to exclude dead OTX related clusters (Still updating) (/afs/cern.ch/atlas/groups/EGamma/OQMaps/OLD: checkOQ_v4.C & ObjectQualityMaps_run152166.root & ObjectQualityMaps_run155118.root) • ETclus>15GeV • |ηclus|<2.0 without crack region (only within TRT coverage for eProbabilityHT, should be 2.5 for Calo Isolation study) • AuthorElectron (author==1 || author==3 for MC AOD, author==1 for data ESD) • isEM Loose/Medium/Tight applied respectively • Track quality requirements: nSCTHits>=6, nPixelHits>0, nTRTHits>=10 • Basic shower shapes requirements: f1>0.01; weta1, dEminS1, dEmaxS1, WstotS1 >0.

  5. ABCD Method 1. (data-driven only, need to verify in MC) Assume ABCD regions have similar ratio over each other for those background components of each region in the data: bgdA/bgdB=bgdD/bgdC So as to extract the signal component in “D” while removing the estimated background in it. (Should be verified based on MC) • ABCD Method 2. (using MC information, limited due to MC and Data disagreement and statistics) Assume ABCD regions have similar ratio over each other for both signal and bgd between data and Monte Carlo: b1i+b2i+si=Ni, i=A,B,C,D • b1i: 1stkind of background (JF17), b2i: 2nd kind of background (filtered_MinBias) Ni: Expected from data • si/si,b1i/b1j, b2i/b2j in data should be consistent with MC • 3 equations and 3 unknown variables • Can be implemented with more or fewer background samples

  6. Electron Probability for TRT High Threshold(variable named eProbabilityHT)VsMET_Topo eProbabilityHTVsMET_Topo • A: MET_Topo <= 25GeV, eProbabilityHT >= 0.9 • B: MET_Topo <= 25GeV, eProbabilityHT < 0.9 • C : MET_Topo > 25GeV, eProbabilityHT <= 0.9 • Signal Region D: MET_Topo > 25GeV, eProbabilityHT> 0.9

  7. eProbabilityHT distribution after preCuts with isEM medium applied (Not Normalized)

  8. D A C B eProbabilityHTVsMET_Topoafter preCuts with isEM medium applied (Not Normalized) A D D A C B C B

  9. isEMLoose(Not Normalized) A/B=D/C doesn’t agree Very tight

  10. isEMMedium(Not Normalized) A/B=D/C doesn’t agree Very tight

  11. IsEM Tight is not appropriate to be applied due to its correlation with the variable eProbabilityHT!

  12. Calorimeter Isolation(CaloIso)VsMET_Topo CaloIsoVsMET_Topo • A: MET_Topo <= 25GeV, CaloIso <= 0.1 • B: MET_Topo <= 25GeV, CaloIso > 0.1 • C : MET_Topo > 25GeV, CaloIso>= 0.1 • Signal Region D: MET_Topo > 25GeV, CaloIso< 0.1

  13. Calorimeter Isolation distribution after preCuts with isEM medium applied (Not Normalized)

  14. B C Calorimeter Isolation VsMET_Topo after preCutswith isEM medium applied (Not Normalized) A D B B C C A A D D

  15. isEM Loose(Not Normalized) A/B=D/C doesn’t agree

  16. isEMMedium(Not Normalized) A/B=D/C doesn’t agree

  17. isEM Tight(Not Normalized) A/B=D/C agrees with the assumption extremely well

  18. Some possibilities for next step TRT High Threshold Probability still need to be further investigated since the results did not agree with assumption in method 1 (try with method 2?) Try with New Recommended Robust isEMTight Cuts Update with new fundamental selection criteria(new GRL, OQMap, etc.) with more new collision runs Some other way: 2-D Matrix method (very simple way to carry on by using only one variable but may result in some disagreement between different variables) Change some values of the current cut criteria and evaluate the systematics

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