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TeVatron SUSY searches in final states leptons and photons

TeVatron SUSY searches in final states leptons and photons. mSUGRA chargino and neutralino trilepton GMSB inclusive search in diphoton plus missing ET. Vu Anh Tuan Laboratoire de l’Accélérateur Linéaire, Orsay, France for CDF and D  collaborations. SUSY@TeVatron (1/2). mSUGRA

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TeVatron SUSY searches in final states leptons and photons

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  1. TeVatron SUSY searchesinfinal states leptons and photons • mSUGRA chargino and neutralino trilepton • GMSB inclusive search in diphoton plus missing ET Vu Anh Tuan Laboratoire de l’Accélérateur Linéaire, Orsay, France for CDF and D collaborations Veme Rencontres du Vietnam, 2004

  2. SUSY@TeVatron (1/2) • mSUGRA • SUSY breaking mediated by gravity • LSP is most likely neutralino 01 • Mass: 1  02  201 • GMSB • Mediated by gauge fields • LSP is gravitino • Phenomenology is entirely determined by NLSP (slepton or neutralino) • Analysis in this talk interpreted within mSUGRA or GMSB frameworks • R-parity conservation missing energy Veme Rencontres du Vietnam, 2004

  3. SUSY@TeVatron (2/2) • Squarks and gluinos • large cross-section • decay most of the time into jets plus MET • huge QCD multijets background • Processes w/ lepton(s) and/or photon(s) in final state (e.g., chargino/neutralino production) • smaller cross-section (BR) • much lower QCD background • Subject of this talk Veme Rencontres du Vietnam, 2004

  4. D trilepton searches Veme Rencontres du Vietnam, 2004

  5. Chargino-neutralino searches • Very clean decay mode: trilepton plus MET • Searches at DØ • Di-electron plus (any) lepton (e,  ou ) • Electron-muon plus (any) lepton • Like-sign dimuon ( ) • Optimized for mSUGRA parameters (near LEP II limit) • tan = 3,  > 0, A0 = 0 • m0 = [72, 88] GeV, m1/2 = [165, 185] GeV • mass 1  02 [97, 114] GeV • mass slepton  1  enhance leptonic decay • BR  0.2-0.4 pb • Integrated luminosity 150-175 pb-1 Veme Rencontres du Vietnam, 2004

  6. eel (1/2) • Backgrounds: Z/DY, W+, diboson, Z/DY , top pair • 2 electrons: isolated, ET > 12(8) GeV, || < 1.1(3.0) • Z veto: keep M(ee) in [15, 60] GeV • DY reduction • (ee) < 2.8 • MET > 20 GeV • Top pair veto: jet veto • W+  (ee) • Require hits in the tracker innermost layers • Third lepton: an isolated track present , pT > 3 GeV • Include e,  and  (even -hadronic decays) Signal Veme Rencontres du Vietnam, 2004

  7. eel (2/2) • Remaining DY background has low MET and track pT • To optimize signal selection • Use the product of MET and track pT • Final cut • METpT(track) > 250 GeV2 • Observed: 1 event • Expect: • 0.27 background event • 0.8-1.6 events from SUSY Veme Rencontres du Vietnam, 2004

  8. el • Background: • Z/DY : dominant • WW, WZ, ZZ, top pair • W+j/, QCD • e: isolated, ET > 12 GeV, pT > 8 GeV • MET > 15 GeV • Similar Z, W+ and top pair vetoes as in eel analysis • Same isolated track (pT > 3 GeV) requirement • Observed: 0 event • Expect: • 0.54 background events • 0.63-0.93 events from SUSY Before track pT > 3 GeV cut Veme Rencontres du Vietnam, 2004

  9. Like-sign dimuon • Backgrounds • b/c pairs (dominant) • W+jets, top pair • Charge sign-flip: Z/DY •   isolated, pT > 5 GeV • bb/cc estimated from data • Calibrated from QCD-dominated region (one µ nearly “isolated”,(µµ) > 2.7) • Charge sign-flip: from MC and cross-checked w/ data • Cuts • µ pT > 11(5) GeV, both isolated, (µµ) < 2.7 • Z veto, MET > 15 GeV • LS mass (µµ) < 80 GeV • Observed: 1 events • Expect: • 0.13 background events • 0.2-0.4 events from SUSY Veme Rencontres du Vietnam, 2004

  10. Combined trilepton • Gain better sensitivity • See 3 events from data, expect 3.4 from SM background • Set a 95% CL limit on trilepton cross-section • Significant improvement over Run I • Approaching mSUGRA sensitivity region • Result interpreted within mSUGRA framework • Can be used to constrain other models with similar mass hierarchy Veme Rencontres du Vietnam, 2004

  11. CDF and D inclusive diphoton search Veme Rencontres du Vietnam, 2004

  12. Inclusive diphoton search (1/3) gravitino gamma quark neutralino SUSY production neutralino gamma gravitino • In GMSB, neutralino could be NLSP • Assume short lifetime  decays well inside detector • SUSY particles decay down to neutralino into gravitino and photon quark • Signature: two photons plus MET in final state Veme Rencontres du Vietnam, 2004

  13. Diphoton search (2/3) • Background • QCD plus photon or jet fake photon (dominant) • Electron fake photon: Z/DY, W+ e+  • QCD: estimated from data • at least one EM cluster fails standard ID cut • QCD dominated at low MET (<20(15) GeV)  normalized to predict contribution at high MET • e: from data • using identified e and scaled by (e) fake rate Veme Rencontres du Vietnam, 2004

  14. Diphoton search (3/3) • Two photons ET > 13(20) GeV, || < 1.0(1.1) • MET > 45(40) GeV • CDF: 202 pb-1, D: 185 pb-1 • Parameters • N = 1, Mmessenger = 2 • µ > 0 • tan = 15 (CDF), 5 (D- Snowmass slope) • Signal dominated by chargino-neutralino production • Observed: 0 (CDF), 1 (D) events • SM background: 0.6 (CDF), 2.5 (D) events Lower limit on neutralino mass CDF: 93 GeV D: 105 GeV (beyond LEP!) Veme Rencontres du Vietnam, 2004

  15. Conclusion • CDF and DØ produce solid physics results based on up to 200 pb-1 of luminosity • Limits exceed Run I • mSUGRA: Trilepton analysis of chargino and neutralino • GMSB: inclusive diphoton • TeVatron luminosity increases steadily • New results coming out soon! 1.00E+32 Veme Rencontres du Vietnam, 2004

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