CDF Logo Search for Chargino-Neutralino Associated Production in e+e,mu+e,mu channel, Public Page Exotics Logo

This Run II analysis is an inclusive search for Chargino-Neutralino associated production in their decay channel with trileptons in 1 fb-1 of data. We concentrate on the decays with one electron and two additional leptons (electrons or muons). The events are selected from the inclusive single high-pt electron trigger which requires Et(electron) greater than 18 GeV. The selection of the events requires one electron with Et greater than 20 GeV and a second lepton with Et greater than 8 GeV (satisfying the electron and muon ID cuts as in the note and as blessed in the Joint Physics meeting), satisfying the topological cuts:
- 20 < Mee < 76 and Mee > 106 GeV/c2;
- Transverse missing energy > 15 GeV;
- DeltaR(ee, emu) > 0.4
- Number Jets (with Et > 20) < 2;
and a third lepton which can be electron or muon with Et > 4 GeV and satisfying the same cuts as the second electron and the muon ID criteria as in the note. The Standard Model backgrounds are evaluated from Monte Carlo samples, while the rate of jets faking leptons is obtained from jet samples at different Et tresholds collected in the data. The analysis is carried out as three separate analyses, depending if the second lepton is a central electron (CC), an electron in the forward (CP) or a muon (EM). We observe zero events in all channels, with an expected background of 0.43 ± 0.06(stat) ± 0.06(syst), 0.33 ± 0.08(stat) ± 0.05(syst), 0.28 ± 0.08(stat) ± 0.03(syst) events for CC, CP and EM respectively. The systematic uncertainty has been evaluated for signal and backgrounfd as in the Tables below. A combination of this analysis with the other trilepton analyses is currently undergoing.


Blessed Plots and Tables:

Invariant mass (Mll), delta phi(dphi), missing transverse energy(MEt) and number of jets(NJets) distributions for events with two electrons on the central, The invariant mass and the delta phi distributions are before any cut, the MEt distribution is after the Mll cut and the NJets is after the Mll and the MEt cuts. EPS or GIF (with nJets on log scale: EPS or GIF )
Each plot singularly :
  • Invariant Mass EPS,GIF
  • Delta Phi EPS,GIF
  • MEt EPS,GIF
  • NJets EPS,GIF (log: EPS,GIF)
  • Invariant mass (Mll), delta phi(dphi), missing transverse energy(MEt) and number of jets(NJets) distributions for events with the second electron is in the plug, The invariant mass and the delta phi distributions are before any cut, the MEt distribution is after the Mll cut and the NJets is after the Mll and the MEt cuts. EPS or GIF (with nJets on log scale: EPS or GIF )
    Each plot singularly :
  • Invariant Mass EPS, GIF
  • Delta Phi EPS,GIF
  • MEt EPS, GIF
  • NJets EPS, GIF (log scale:EPS, GIF)
  • Invariant mass (Mll), delta phi(dphi), missing transverse energy(MEt) and number of jets(NJets) distributions for events with the two electrons (CC+CP), The invariant mass and the delta phi distributions are before any cut, the MEt distribution is after the Mll cut and the NJets is after the Mll and the MEt cuts. EPS or GIF (with the NJets distribution in log scale: EPS or GIF ).
    Each plot singularly :
  • Invariant Mass EPS, GIF
  • Delta Phi EPS,GIF
  • MEt EPS, GIF
  • NJets EPS, GIF (log scale: EPS, GIF)
  • Invariant mass (Mll), delta phi(dphi), missing transverse energy(MEt) and number of jets(NJets) distributions for events when the second lepton is a muon, The invariant mass and the delta phi distributions are before any cut, the MEt distribution is after the Mll cut and the NJets is after the Mll and the MEt cuts. EPS or GIF (with nJets on log scale: EPS or GIF )
    Each plot singularly :
  • Invariant Mass EPS, GIF
  • Delta Phi EPS,GIF
  • MEt EPS, GIF
  • NJets EPS, GIF (log scale: EPS, GIF)
  • Missing energy distribution between the first two electrons (CC) for events with two electrons in the invariant mass window 76-106 GeV/c2 (Control Region Z).
    EPS or GIF
    Jet multiplicity (for jets with Pt greater than 20 GeV) for events with two electrons (CC) in the invariant mass window 76-106 GeV/c2 (Control Region Z).
    EPS or GIF
    Pt of the leading lepton for events with two electrons (CC) in the invariant mass window 76-106 GeV/c2 and missing energy greater than 15 GeV (Control Region E).
    EPS or GIF
    Pt of the sub-leading lepton for events with two electrons (CC) in the invariant mass window 76-106 GeV/c2 and missing energy greater than 15 GeV (Control Region E).
    EPS or GIF
    Pt of the leading lepton for events with two electrons (CC) in the invariant mass window 20-76 and > 106 GeV/c2, missing energy greater than 15 GeV and number of jets (with Et < 20 GeV) less than 2 (Signal Region A).
    EPS or GIF
    Pt of the sub-leading lepton for events with two electrons (CC) in the invariant mass window 20-76 and > 106 GeV/c2, missing energy greater than 15 GeV and number of jets (with Et < 20 GeV) less than 2 (Signal Region A).
    EPS or GIF
    Missing transverse energy for three leptons events (CC+lepton) in Signal Region A after all the cuts but the missing energy itself are applied.
    EPS or GIF
    Missing energy distribution between the first two electrons (CP) for events with two electrons in the invariant mass window 76-106 GeV/c2 (Control Region Z).
    EPS or GIF
    Pt of the leading lepton for events with two electrons (CP) in the invariant mass window 20-76 and > 106 GeV/c2, missing energy greater than 15 GeV and number of jets (with Et < 20 GeV) less than 2 (Signal Region A).
    EPS or GIF
    Missing transverse energy for three leptons events (CP+lepton) in Signal Region A after all the cuts but the missing energy itself are applied.
    EPS or GIF
    Missing transverse energy for three leptons events (CC+lepton + CP+lepton) in Signal Region A after all the cuts but the missing energy itself are applied.
    EPS or GIF
    Pt of the leading lepton for events with one electron and one muon (EM) in the invariant mass window 20-76 and > 106 GeV/c2, missing energy greater than 15 GeV and number of jets (with Et < 20 GeV) less than 2 (Signal Region A).
    EPS or GIF
    Pt of the sub-leading lepton for events with one electron and one muon (EM) in the invariant mass window 20-76 and > 106 GeV/c2, missing energy greater than 15 GeV and number of jets (with Et < 20 GeV) less than 2 (Signal Region A).
    EPS or GIF
    Missing transverse energy for three leptons events (EM+lepton) in Signal Region A after all the cuts but the missing energy itself are applied.
    EPS or GIF
    Jet multiplicity (for jets with Pt greater than 20 GeV) for events with one electron and one muon (EM) in the invariant mass window 76-106 GeV/c2 and missing energy greater than 15 GeV (Control Region E).
    EPS or GIF
    Rapresentation of the control regions used in this analysis, as a function of invariant mass and missing energy, for high and lot jet multiplicity.
    EPS or GIF
    Table showing the number of dilepton expected events from the SM processes and the fakes and the expected number of signal events together with the observed events for each control region for events with two central electrons (CC).
    EPS or PDF or GIF
    Table showing the number of dilepton expected events from the SM processes and the fakes and the expected number of signal events together with the observed events for each control region for events with one central electron and one plug electron (CP).
    EPS or PDF or GIF
    Table showing the number of dilepton expected events from the SM processes and the fakes and the expected number of signal events together with the observed events for each control region for events with one central electron and one muon (EM). The number of observed trilepton events in all control regions is zero, with 0.68 ± 0.16 ± 0.13 expected from SM background.
    EPS or PDF or GIF
    Table showing the number of trilepton expected events from the SM processes and the fakes and the expected number of signal events together with the observed events for each control region for events with two central electrons (CC).
    EPS or PDF or GIF
    Table showing the number of trilepton expected events from the SM processes and the fakes and the expected number of signal events together with the observed events for each control region for events with two central electrons (CP).
    EPS or PDf or GIF
    Table showing the sources of systematic uncertainty and their contributions for the signal.
    EPS or PDF or GIF
    Table showing the sources of systematic uncertainty and their contributions for the SM background.
    EPS or PDF or GIF
    Final table showing the total of the background and the expected and observed events.
    EPS or PDF or GIF


    This Page was last updated September 7th, 2006 by Giulia Manca.
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