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Four top search in hadronic channel

Analysis plan, simulation studies, event selection criteria, and reconstruction methods for searching four top quark production in the hadronic channel using CMS data at 13 TeV.

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Four top search in hadronic channel

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  1. Four top search in hadronic channel SEP. 5, 2017 JONGSEOK LEE ( SUNGKYUNKWAN UNIVERSITY)

  2. Contents • Plan for 2016-2017 • Four top search • Displaced muon perfomance (service work) • Phi asymmetry in FLUKA simulation (service work) • Geant4 simulation (service work) • Plan for 2017-2018

  3. Plan for H++ analysis at 2016 & 2017

  4. Plan for service work at 2016 & 2017 Complete

  5. Feynman diagrams for 4top Leading-order Feynman diagrams for 4top production in the SM from gluon-gluon fusion (left) and quark-antiquark annihilation (right)

  6. Decays of a top quark _ q ν q l b b W W t t Hadronic (left) and Leptonic (right) decays of a top quark

  7. W+ decay modes BR(4top  hadrons) = 20%

  8. Channels of top

  9. Number of jets IsHadronTrig // jet_pt>30, |jet_eta|<2.4, jet_LooseId normalized to 1 normalized to 1 normalized to 1 normalized to 1 9

  10. HT IsHadronTrig normalized to 1 normalized to 1

  11. Cut criteria • Step1(Skim) : NJet>=6, NBJet>=2 • Step2(HLT) : IsHadronTrig • Step3(Event selection for ttbar) : HT>600 • Step4(Event selection for lepton channel) : (NLooseMuon+NLooseElectron)==0&&MET<100 • Step5(Events selection for ttbar) : NJet>=10&&NBJet>=3

  12. Cut efficiency

  13. Cut efficiency

  14. Number of expected events at 36fb-1

  15. HT at 36fb-1 IsHadronTrig 15

  16. HT at 36fb-1 IsHadronTrig 16

  17. Cut criteria • Step1(Skim) : NJet>=6, NBJet>=2 • Step2(HLT) : IsHadronTrig • Step3(Event selection for ttbar) : HT>600 • Step4(Event selection for lepton channel) : (NLooseMuon+NLooseElectron)==0&&MET<100 • Step5(Events selection for ttbar) : (NJet-NBJet)>=8&&NBJet>=4

  18. Number of expected events at 36fb-1

  19. W and top reconstruction 1. Choose 1st~8th highest pt jet 2. Choose a best 4Mjj combination by minimum(|MW - <Mjj>|) 3. Choose 1st~4th highest pt bjet 4. Choose a best 4Mjjb combination by minimum(|Mtop - <Mjjb>|)

  20. ΔRmin and number of particles

  21. <Mjj> of best 4Mjj NJet>=6, NBJet>=2, IsHadronTrig normalized to 1

  22. Number of Mjj in best 4Mjj NJet>=6, NBJet>=2, IsHadronTrig normalized to 1 22

  23. <Mjjb> of best 4Mjjb NJet>=6, NBJet>=2, IsHadronTrig normalized to 1

  24. Number of Mjjb in best 4Mjj NJet>=6, NBJet>=2, IsHadronTrig normalized to 1 24

  25. Number of expected events at 36fb-1 • Step1(Skim) : NJet>=6, NBJet>=2 • Step2(HLT) : IsHadronTrig • Step3(Event selection for ttbar) : HT>600 • Step4(Event selection for lepton channel) : (NLooseMuon+NLooseElectron)==0&&MET<100 • Step5(Events selection for ttbar) : NW>=4&&Ntop>=3

  26. Displaced muon perfomance • Development of displaced muon gun • Production of displaced muon gun sample • Analysis

  27. Parameters for simulation • CMSSW_8_1_0_pre6 • d0_max = 250cm • d0_min = 20cm • eta_max = 2.9 • eta_min = -2.9 • pt_max = 100 • pt_min = 1.0 • 40k events

  28. Efficiency : PT VS η(displaced stand alone muon) 28

  29. Efficiency : PT VS η(displaced stand alone muon) 29

  30. Efficiency : dz VS η(displaced stand alone muon) dz vs η (≡a=b/c, efficiency) dz vs η (≡b, associated) dz vs η (≡c, simulated) 30

  31. Phi asymmetry in FLUKA simulation 31

  32. phi asymmetry in CSCs Background rate Jian Wang’s slide FLUKA simulation 5k events Normalized to L=10.9x10E33 Hz/cm2 Version 3.0.0.0

  33. phi asymmetry in RE-4 Data FLUKA simulation 5k events Normalized to L=1x10E34 Hz/cm2 Version 3.0.0.0

  34. phi asymmetry in DTs 34

  35. Geant4 simulation • Installation and tutorial : https://indico.cern.ch/event/636105/contributions/2574992/attachments/1452248/2239804/170502_Jongseok_Lee_Geant4_installation_and_tutorial.pdf 35

  36. Electron scattering Aluminium foil 0.52mm e- 13MeV

  37. Electron scattering (13MeV, Al) log scale normalization 37

  38. Simplified calorimeter with layers of two materials e- 50MeV

  39. e- beam (50MeV)

  40. Energy deposit VS Track length e- 50MeV e- 50MeV dE/dx = 1/5 e- 500MeV e- 500MeV

  41. Synchrotron radiation 1 Tesla vacuum 500m3 e 10GeV

  42. e 10GeV, 1Tesla, 500m3

  43. Plan for 2017-2018

  44. backup

  45. 2017년도 이론물리 대학원생 파견 공모 https://www.nrf.re.kr/biz/notice/view?nts_no=94429&menu_no=44&biz_no=&search_type=&search_keyword=&page=k

  46. 2017년도 한-스위스 박사과정생 연수사업 신규과제 공모 https://www.nrf.re.kr/biz/notice/view?nts_no=93878&menu_no=&biz_no=&search_type=ALL&search_keyword=&page=6

  47. top trigger  Trigger for 2016 Run2016B-H 25 ns 23Sep2016ReReco data with RunIISummer16 Moriond17_80X MC https://twiki.cern.ch/twiki/bin/viewauth/CMS/TopTrigger

  48. Number of leptons IsHadronTrig tight leptons normalized to 1 tight leptons normalized to 1 loose leptons normalized to 1 loose leptons normalized to 1 48

  49. MET IsHadronTrig normalized to 1 normalized to 1

  50. Search for standard model production of four top quarks in proton-proton collisions at 13 TeV (CMS PAS TOP-16-016) • A search for events containing four top quarks has been performed • using 2.6 fb-1 of data recorded by the CMS experiment at 13 TeV. • The analysis focuses on a combination of the single lepton channel in the μ + jets and e + jets final states and dilepton channel in the μμ, μe, and ee final states. • An event classification scheme based on a BDT algorithm is defined. • ex) BDT = jet_pt*0.1 + sin(pt*3) + cos(Njets) BDT output distribution in the μ+jets channel

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