Status of the LQ1 search in the final states 2e 2jets and e 2jets

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Status of the LQ1 search in the final states 2e
2jets and e ? 2jets
A.F Barfuss M.C Cousinou

• The data CAF trees and cafe tools
• Methods we are planning to use to determine the
  Multijet (MJ) background
• The SM background MC files we have found
• The signal Leptoquark scalar (pythia) and
  vector (comphep)

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The Data

• CAF trees in Lyon
• The 2e 2j final
  state
• CSG_CAF_2EMhighpt_PASS3 (actually 1014 files)
• Triggers a list of 2 EM objects or one high ET
  EM cluster as in the preceeding analysis
• The e ? 2j final
  state
• CSG_CAF_EMinclusive_PASS3 (actually 8562 files)
• Triggers EM_MX ( V8 ? V11) loose electron with
  ETgt30 GeV
• E1_SH30 (V12 ?V13) loose
  electron with ETgt30 GeV loose shower shape
  requirements
• E1_ISH30 (V14) loose
  isolated electron with ETgt30 GeV loose shower
  shape requirements

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Preselection of the 2EMhighpt skim filesp18.07.00

• 2 electrons (emid_cuts.txt Tight v1)
• Id10,11 emfracgt0.9 isolt0.15
  PTgt8 GeV
• spatial track match ( TrkMatchChi2
  0.01 )
• ( HMx7lt12 (CC) or HMx8lt20 (EC) )
• Primary vertex Z lt60.cm at least 2 tracks
• Reject EM jets (JCCB) with ?R(jet-electron)lt0.5
• Apply JES
• 2 jets (corrJCCB) with ETgt15 GeV and ?lt2.5
• 29.480.209 events (1014 files)
  ? 3657 preselected events
• Cut on PT(electrons)? 25 GeV
  
• Cut on PT(jets) ? 25 GeV
  events

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Method to find the QCD background in the 2e 2j
final state

• We use 2 samples of
  data
• 2 EM clusters 2 jets
• ET(EM1,EM2)gt25 GeV , 2 track matched
  (spatial) and ET(jet1,jet2)gt25 GeV
• 2 EM clusters 0 jet
• ET(EM1,EM2)gt25 GeV and 2 track matched
  (spatial)
• These 2 samples are
  themselves split in 2 sub samples
• The 2 EM clusters are Tight (cut on HMX)
  (Z/DY Multijet events)
• The 2 EM satisfy a reverse HMX condition
  (Multijet events)
• We assume
  that
• NMJ(Data 2j)/NMJ(QCD 2j) NMJ(Data
  0j)/NMJ(QCD 0j)
• The samples (QCD 2j) and (QCD 0j) contain only MJ
  events ?NMJ(QCD 2j) and NMJ(QCD 0j) are known ,
  but NMJ(data 0j) N(data 0j) NZ/DY(data 0j)
  and we will determine
• NZ/DY(data 0j) using Monte Carlo events
• Method developed by Fu in the p14 analysis

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Method to find the QCD background in the e ?2j
final state

• The data sample
  is split in 2 sub samples
• Data
• EM Tight (HMx7?12 in CC ) or (HMx8?20 in EC )
  and ET ? 35GeV
• track match (E/P) and track isolation
• 2 jets (ET ? 25GeV)
• angular cuts between the ETmiss and the EM
  cluster or the jets to remove
• instrumental ETmiss
• QCD
• EM with HMX cuts reversed and ET ? 35GeV
• spatial track match and track isolation
• 2jets (ET ? 25GeV)
• angular cuts between the ETmiss and the EM
  cluster or the jets to remove
• instrumental ETmiss
• We assume that the 2 samples, at low values of
  the ETmiss, are both multijets.
• So we normalize the QCD to the Data for
  ETmisslt10 GeV and use the QCD

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Z 2jets Background

• Pythia release p17.06.02 tmb fixed with
  p17.08.01
• CAF trees p18.03.00

• ALPGENPythia release p17.09.01
• CAF trees CSG_CAF_MCv3_xxxxx (xxxxx is the
  request ID)
• Z?ee 0j exclusive M(ee) 60-130 GeV
• request ID 29270 , 29271 , 29276 , 29277

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W 2jets Background

• Release p17.09.01 - fixed with
  p17.09.05 -
• CAF trees created with
  p18.05.00

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Signal simulation (1)

• Scalar LQ with Pythia M(LQ) 120 to 320
  GeV
• for the 2e 2j and e ? 2j final states
  (10000 events /mass)
• Vector LQ with Comphep M(LQ)250 GeV
• for the 2e 2j final state
• Comphep version v4.2-p1 including scalar
  and vector LQ
• Hep-ph/0502067 A. Belyaev et al - many
  possible LQ we have chosen
• VM vector leptoquark S1 F-2 Qem1/3
  (e ubar)
• S0 scalar leptoquark S0 F-2
  Qem1/3
• F3BL with B baryon number and L lepton
  number

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Signal simulation (2)

• KG and ?G are anomalous couplings related to the
  anomalous magnetic and quadrupole moments of
  vector LQ
• Cross sections and LQ polarization are dependent
  of the values of KG and ?G
• About 10000 events have been generated for 3
  traditional choices of KG and ?G

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and ? distributions of the lepton and the
quarkscalar LQ (pythia) M(LQ)250 GeV
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ET distributions of the lepton and the
quark(generator level)
?
About 17 more events in the S0 sample than in
the pythia sample
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M(eu) scalar LQ (pythia) M(LQ)250 GeV
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Opening angle between the e and the quark of the
LQat the generator level