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Higgs  ZZ  e + e - νν using CMSSW_0_8_0

A study on. Higgs  ZZ  e + e - νν using CMSSW_0_8_0. Outline. Signal & Background Description Electron Identification Missing Energy Z Invariant Mass EndCap SuperClusters software bug. ISUB. Which?. 24. f i f ibar  Zh 0. 26. f i f jbar  W + h 0. 102. gg  h 0.

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Higgs  ZZ  e + e - νν using CMSSW_0_8_0

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  1. Christos Lazaridis, UW-Madison, CMS Group A study on... Higgs  ZZ  e+e-νν using CMSSW_0_8_0

  2. Christos Lazaridis, UW-Madison, CMS Group Outline • Signal & Background Description • Electron Identification • Missing Energy • Z Invariant Mass • EndCap SuperClusters software bug

  3. Christos Lazaridis, UW-Madison, CMS Group ISUB Which? 24 fi fibarZh0 26 fi fjbarW+h0 102 gg  h0 123 fifj fifjh0 124 fifj fkflh0 Signal Characteristics • Higgs ZZ e+e-νν • Higgs mass set at 300 GeV • Turned off all Higgs decays except the desired one • Forced one Z to decay to electrons; the other to neutrinos • Cross section: • 6.60*10-11 mb Pythia parameters:

  4. Christos Lazaridis, UW-Madison, CMS Group ISUB Which? 15 fifibargZ 16 fifjbargZ 30 figfiZ Background Characteristics • 4 Background sets: • Single Z • Total cross section: • 5.35x10-3 mb Pythia parameters:

  5. Christos Lazaridis, UW-Madison, CMS Group ISUB Which? 19 fifibarγZ 22 fifibarZZ 23 fifjbarZW+ 25 fifibarW+W- Background Characteristics • 4 Background sets: • Vector Boson fusion • Total cross section: • 2.35x10-5 mb Pythia parameters:

  6. Christos Lazaridis, UW-Madison, CMS Group ISUB Which? 81 fifibarQkQkbar 82 ggQkQkbar Background Characteristics • 4 Background sets: • Top quark • Total cross section: • 6.88x10-6 mb Pythia parameters:

  7. Christos Lazaridis, UW-Madison, CMS Group ISUB Which? 1 fifibarγ*/ Z Background Characteristics • 4 Background sets: • Drell-Yan • Total cross section: • 3.27x10-3 mb Pythia parameters:

  8. Christos Lazaridis, UW-Madison, CMS Group Higgs Pt Pt distribution in agreement with M. Grazzini et al. Higgs Pt (GeV/c)

  9. Christos Lazaridis, UW-Madison, CMS Group Cuts to identify electrons Starting with 4961 Signal Events. 2621 survive after -1.5<η<1.5 (53%) : 8149 Initial SCs Selecting energetic SuperClusters: • 10 GeV ≤Et,SC≤ 500 GeV 6432 Remain (78.9%) Reject Hadronic Jets • ΔRSCs & Jets≥ 0.15 • Et,SC/Et,Jet≥ 0.3 6089 Remain (74.3%) Select SCs with matching Track • Pt,Track≥ 10 GeV • ΔRTracks & SCs≤ 0.15 • Et,SC/Pt,Track≥ 0.7 4270 Remain (52.4%)

  10. Christos Lazaridis, UW-Madison, CMS Group Choosing ΔRSCs & Jets & ΔRTracks & SCs ΔR between SCs & Closest Jet ΔR between SCs & Closest Track

  11. Christos Lazaridis, UW-Madison, CMS Group Gene vs. Reco Electrons Et • Very good agreement between the two distributions 2 Highest Generated Electrons Et Electron Candidates Et Et (GeV)

  12. Christos Lazaridis, UW-Madison, CMS Group Generated vs Reconstructed η • Minimal matching: • Ereco = 0.8~1.2 Egene • Good agreement

  13. Christos Lazaridis, UW-Madison, CMS Group Generated vs Reconstructed φ • Minimal matching: • Ereco = 0.8~1.2 Egene • We are reconstructing the generated electrons

  14. Christos Lazaridis, UW-Madison, CMS Group Variable Selects against... Z mass WW, Top, Drell-Yan Electron Et Fake electron, combinatoric Z Pt Fake Z, Drell-Yan Missing Et Z bg (maybe not top or W) Higgs Selection Variables • HiggsZZe+e-νν main backgrounds: • Single Z • Vector Boson fusion • Top • Drell-Yan

  15. Christos Lazaridis, UW-Madison, CMS Group Signal/Bg comparison(only 2 bg sets) Electron Candidates, Et Et (GeV)

  16. Christos Lazaridis, UW-Madison, CMS Group Reco Z Invariant Mass • Fitting range • 70-110 GeV • Very good Z mass reconstruction Inv. Mass (GeV/c2)

  17. Christos Lazaridis, UW-Madison, CMS Group Missing Et(gene vs reco) • Reconstructed MET looks narrow • Still investigating MET (GeV)

  18. Christos Lazaridis, UW-Madison, CMS Group EndCap SCs Software bugGenerated vs Reconstructed φ BARREL • To find them: Just require that η or φ is a number. All bogus give “nan”. ENDCAPS Absolutely no trend! • Energies vary from slightly negative values (found a SC with -0.325042) up to 1200 GeV! • All of them are in the EndCaps.

  19. Christos Lazaridis, UW-Madison, CMS Group EndCap SCs Software bugGenerated vs Reconstructed η BARREL ENDCAPS

  20. Christos Lazaridis, UW-Madison, CMS Group EndCap SCs Software bugSC Energy SuperCluster Energy GeV

  21. Christos Lazaridis, UW-Madison, CMS Group Conclusions • Electron reconstruction seems to be very efficient – the selected cuts are doing a pretty good job. • Thanks to A. Nikitenko for his help with the full framework analysis and to S. Rahatlou for his help with the buggy EndCap SCs. • Source code and complete journal of how this summer progressed can be found at: http://www.hep.wisc.edu/~lazaridis

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