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Tibor Kurča IPN Lyon

Recent Results of SUSY Searches at the Tevatron Collider. Tibor Kurča IPN Lyon. On behalf of CDF & D0 collaborations. DIS 2004 Štrbské Pleso, Slovakia 14.-18. 4. 2004. Outline. Tevatron and CDF & D0 detectors upgrades Supersymmetry searches Direct: * in mSUGRA:

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Tibor Kurča IPN Lyon

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  1. Recent Results of SUSY Searches at the Tevatron Collider Tibor Kurča IPN Lyon On behalf of CDF & D0 collaborations DIS 2004 Štrbské Pleso, Slovakia 14.-18. 4. 2004

  2. Outline • Tevatron and CDF & D0 detectors upgrades • Supersymmetry searches • Direct: * in mSUGRA: 3-leptons + mET(charginos, neutralinos) jets + mET (squarks, gluinos) *in mGMSB: 2-photons + mET(charginos, neutralinos) • Indirect: Rare B-meson decays (lightest Higgs) • Summary DIS 2004 Tibor Kurca

  3. Chicago  CDF DØ Tevatron p source Main Injector & Recycler Tevatron Upgrade - RUN II • Higher energy: • √s = 1.8 TeV  1.96 TeV • Higher cross sections (30-40 % for SUSY) • More(anti)protons/bunch (New Main Injector & Recycler) • More bunches: 6x6  36x36 bunches (3.5 s  396 ns) • Higher luminosity Run I : 2x1031 cm-2s-1 Run II : 2.9x1032 cm-2s-1 DIS 2004 Tibor Kurca

  4. Muon forward chamber   2 • Calorimeter electronics • Trigger system • DAQ system • Solenoid (2 T) • Central tracker (SciFi)   1.7  L1 • Silicon vertex detector   3  L1 • Preshower – Central & Forward D0 Detector – Run II DIS 2004 Tibor Kurca

  5. CDF Detector – Run II • New Si Tracker: • ||< 2; 7-8 layers • Central Drift Chamber: •  1.0; 96 layers • Solenoid/ Time of Flight 150 ps /150 cm • Muon Drift Chambers • Muon Scintil. Counters extended coverage ||= 1  1.5 • Forward Calorimeter 1.1  3.5 • Trigger : • COT tracks at L1 • Silicon tracks at L2 • DAQ DIS 2004 Tibor Kurca

  6. Run II Data Taking Presented analyses are based on data taken before Sept 2003 All results are preliminary ! Sept 2003 Physics Analysis Sample ∫ℒ dt  200pb-1 DIS 2004 Tibor Kurca

  7. SUSY Particles Spectrum Rp-conservation produced in pairs  existence of stable LSP DIS 2004 Tibor Kurca

  8. Trileptons in mSUGRA • 3-leptons (isolated) final state – « gold plated channel » • Challenges: - low x-section (EW-production) - rather soft leptons ! • Background: W+Z  ℓ ℓ ℓ • mSUGRA mass assumptions: • Search in 3 channels: • 2e + lepton • e +  (+lepton) combined results  higher sensitivity • 2 LS  DIS 2004 Tibor Kurca

  9. mSUGRA Trileptons: 2e + ℓ (1) ℒ dt = 17511/pb Background rejection • Z:15<Mee<60 GeV (ee) <2.8 • We(+):  1 hit in silicon or tighter e-likelihood • jets: veto jets ET>80 GeV scaled mET > 20 GeV • Drell-Yan: mET>20 GeV (e,mET)>0.4 ‘Wannabe’ signal DIS 2004 Tibor Kurca

  10. mSUGRA Trileptons: 2e + ℓ (2) • 2 electrons, track matched: pT > 12 (8) GeV,  1.1 (3.0) • mET > 20 GeV • 3rd lepton isolated high-quality track • Final cut: mET  pT(track) > 250 GeV • (signal) = 2 – 3 % DIS 2004 Tibor Kurca

  11. mSUGRA Trileptons: 2e + ℓ (3)  • expected signal events 0.8 – 1.6 ; tan  =3, m =(100-115)GeV • expected bgr 0.3 + 0.4 – 0.3 (Zee, WWe e; limited MC statistics) • 1 event observed : pT1=33.3, pT2=25.7, pTtrack=8.6 mET=52.1 GeV DIS 2004 Tibor Kurca

  12. mSUGRA Trileptons: e +  (+ ℓ) (1) ℒ dt = 15810/pb Selection cuts: • goode , with isolated, matching tracks: pTe>12, pT>8 GeV;  - also calorimeter isolation • mET > 15 GeV • minimal transversal mass: 15<minMT(e, )<80 GeV (Z/*, WW cut) • no dileptons with masses around MZ veto 70-110 GeV, (, ) < 2.5; (,e) > 0.3 • jet veto : pT> 60 GeV (1-jet events) (anti tt) pT1 > 40 , pT2 >30 GeV (2 jets) • anti -conversion cut: silicon (SMT) hits 3 for e-track (W) DIS 2004 Tibor Kurca

  13. mSUGRA Trileptons: e +  (+ ℓ) (2) • 2 subselections: (a) imbalance between pTe, pT and MET: ( for e +  , 3rdℓ missing ! anti WW cut) (b) 3rd lepton isolated high-quality track pT>3 GeV ( hollow cone, track from the same vtx as other 2, CFT hits..) most of the remaining bgr↘… but also signal↘ • Results: expected signal events 0 – 0.9 ; tan =3, m =(97-114), m° =(57-67) expected bgr : (a) 2.87  0.36 1 event observed (Z/*->, WW,W+jets/ )(b) 0.54  0.24 no event observed ± DIS 2004 Tibor Kurca

  14. Like-Sign Dimuon Channel (1) ℒ dt = 14710/pb • Idea: 3ℓ  2LS-leptons…. profit from increased acceptance, while reducing bgr • Challenge:modelling bgr tt, W+jets, WZ, ZZ  Monte Carlo - taken from data • Selection Cuts: 2 track-matched, isolated like-sign ,  (, )<2.7 pT1 > 11 , pT2 > 5 GeV, mET > 15 GeV topology to kill bb:if pT2 < 11 GeV  (jet,mET) < 2.4; min(mET, )>0.5, max(mET, )<2.4, mass cuts to kill Z: OS  - M(, )<70 or M(, )>110 GeV LS  - M(, )<80 GeV (avoid sign flip) DIS 2004 Tibor Kurca

  15. mSUGRA LS Dimuon Channel (2) • Data points: M(,) – isolated LS • Shaded histogram: remaining bgr estimated from nearly-isolated LS data • Results - events: expected signal : 0 – 0.4; (tan =3, m =(97-114), m°=(57,67) ) expected bgr: 0.13  0.04(bb, WZ, ZZ, Z) observed:1 eventpT1=29.1, pT2=13.8, LSmass=37.8, mET=33.5GeV, =1.55 ± DIS 2004 Tibor Kurca

  16. SUSY Trileptons – Combined Result (1) ± • mSUGRA :tan  =3, >0,A0=0, m0=(72,88), m½=(165,185) m  m°  2m° 2e + ℓ e +  (+ ℓ )combined using Likelihood Ratio Method 2 LS  • signal overlap15 % (5%) between e++ℓ (e+)  e+e+ℓ , negligible for LS-dimuon analysis • overlapevent assigned to channel with the highest S/B • correlated errors taken into account (main ℒ uncertainty) 1 2 1 DIS 2004 Tibor Kurca

  17. SUSY Trileptons – Combined Result (2) • significant improvement of Run I limit • not reaching mSUGRA prediction yet … constrain more generic SUSY models with compatible mass hierarchies DIS 2004 Tibor Kurca

  18. Squarks & Gluinos Search in mSUGRA • Squarks, gluinos pair production dominates(if light enough…) - consider only 1st & 2nd families with degenerate masses - decay chains depend on mass relations - general event signature: n-jets + MET +m-leptons • Have a look at : production & 2-body decays dominate Background: QCD, W/Z+jets Signature:2 acoplanar jets + mET DIS 2004 Tibor Kurca

  19. Squarks & Gluinos – Event Selection Data : ℒ dt = 85 pb -1 • Jets + Missing ET Trigger (L2, L3) from April 2003 •  2 jets (cone 0.5) in acoplanar topology pT1 60, pT2 50 GeV, det1 0.8 - SM, QCD bgr • not EM-object –jet1,jet2(emf<0.95) • no EM-objectwith pT>10 GeVW/Z+jets • no isolatedwith pT>10 GeV • anti -wrong vertex, -cosmics (cpf>0.05) • mET  60 GeV QCD (moderate MET/correlated with jets) • 30  (mET,jet) 165  • Final cuts: mET  175 GeV, HT(=Etjets)  275 GeV (optimized for m½=130 GeV ) DIS 2004 Tibor Kurca

  20. Squarks & Gluinos Search : Results (2) mET > 175 GeV HT > 275 GeV Observed 4 events Expected 2.7 ± 0.95 DIS 2004 Tibor Kurca

  21. Squarks & Gluinos Search: Results (1) • observed 4 events • expected 2.7  0.95 • Systematics • luminosity: 6.5 % • cross-sections: 8% SM bgr; 10% signal (from Prospino) • jet energy scales (data & MC): • +77% -43% SM background • +20% -15% signal efficiency DIS 2004 Tibor Kurca

  22. Squarks & Gluinos Mass Limits • Signal x-section:PYTHIA (LO) + k-factors PROSPINO (NLO) • mSUGRA parameters:m0 = 25 GeV, A0 = 0, tan  =3, <0 m½ = 100 - 140 GeV scan in 5 GeV steps Mass limits: Msquark > 292 GeV, Mgluino > 333 GeV DIS 2004 Tibor Kurca

  23. Pairs production - large tan  3rd generation sparticles could be light due to large mixing Gluino production Sbottom Quarks Production @Tevatron DIS 2004 Tibor Kurca

  24. Sbottom Quarks from Gluinos 4 bjets + MET Background: -QCD, Top, W/Z+jets Preselection cuts:Signal cuts:  3 jets 15 GeV,  < 2 mET > 50 GeV mET > 35 GeV 1 b-tag svx lepton veto (EW bgr) 2 b-tags svx (mET,jets) (QCD bgr) Assuming: Btag Observed evts Expected Bgr Expected Signal ================================================= Single 4 5.6  1.4 10.6  1.7 Double 1 0.5  0.1 4.4  0.9 ℒ dt = 38.4/pb DIS 2004 Tibor Kurca

  25. Sbottom & Gluino Limits DIS 2004 Tibor Kurca

  26. Gauge Mediated SUSY Breaking CDF Run 1 • SUSY breaking at a scale  ~10-100 TeV (<< GUT) mediated by new gauge fields – « messengers » • LSP is gravitino - very light M( ) < 1 keV • if NLSP is neutralino: ( also possible) Exp. Signature: 2 photons + mET • Assume prompt NLSP decay  photons pointing to interaction vtx DIS 2004 Tibor Kurca

  27. mGMSB 2 +mET search : Analysis • Background:1. fake mET-mismeasured jets, vtx 2. real mET- lost e-track, fake  W  e  (dominant), Wj e j, Z, WW, WZ, top • Event selection:2 isolated photonsET> 20 GeV, det,  no matching tracks, no tracks in hollow cone(0.05, 0.4)  pT < 2 GeV - topology : (mET,jet1) < 2.5 (mET,  ) > 0.5 - optimized mET > 40 GeV • Signal:looking for excess in tails of mET distribution mET (GeV) DIS 2004 Tibor Kurca

  28. mGMSB 2 +mET search : Results ℒ dt = 18512/pb • Observed rates consistent with SM • New limits: • Errors:reco eff. 5% MC-accept. 6%, ℒ 6.5% • mGMSB parameters - scale of SUSY breaking Mm=2- messenger mass scale tan  = 5- vev’s ratio  > 0– sign of higgsino mass term World’s best ! 95% CL  (TeV) DIS 2004 Tibor Kurca

  29. mGMSB 2 +mET : CDF Results • Event selection:2 isolated photons ET> 13 GeV, det, mET > 25 GeV • Expected events: bgr 2 ± 1 ± 1; signal 6.6 • 2 events found • Mass limit : • tan =15, >0, M=2, N5 =1 ℒ dt = 84/pb  (TeV) DIS 2004 Tibor Kurca

  30. Rare B-meson Decays – Indirect SUSY Search • SM prediction: • FCNC decay - very sensitive probe beyond SM • not observed yet , best limit is CDF-I • Can be very strongly enhanced for high tan() SUSY  complements 3-lepton search SUSY predicts enhancement by 10-1000 ! … in mSUGRA correlation with a • search in M=±80 MeV centered on world average Bs(Bd) value  DIS 2004 Tibor Kurca

  31. Rare B-meson Decays: Results ℒ dt = 171/pb • expected events:1.05 ± 0.30 … Bs 1.07 ± 0.31 … Bd 1.75 ± 0.34 … combined • found 1 event :M() = 5.295 GeV … in both windows  Limits @ 90% CL : … 3x better than Run I … BELLE@LP03 1.6E-7 DIS 2004 Tibor Kurca

  32. Summary • Presented results based on ℒ ≤ 185 /pb • Tevatron experiments are exploring « Terra Incognita » limits extended beyond Run I : - 3ℓ + mET - jets, b-jets + mET - GMSB 2 + mET • Many analyses in progress, first Run II papers coming soon • Tevatron performance improving  end of 2004 on tape ~ 0.5 /fb • Better optimized analyses  higher sensitivity to signal • Excellent opportunity for exciting physics at the highest energy frontier Hic Sunt Gluinos DIS 2004 Tibor Kurca

  33. FY’04 Integrated Luminosity Measured luminosity Integrated Luminosity (fb-1) 11/23/03 1/18/04 3/14/04 12 pb-1 / week is also above the design projection design: challenging base: conservative 36×36 bunches 396 ns bunch crossing Start of Fiscal Year Luminosity Prospects DIS 2004 Tibor Kurca

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