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News from ~1fb -1 of e + e - data at E cm =192-202 GeV

News from ~1fb -1 of e + e - data at E cm =192-202 GeV. Nikos Konstantinidis UC Santa Cruz. Outline. New physics in SM processes photons, WW, ZZ… Direct searches Higgs and SUSY The future LEP at Y2K, after LEP?. LEP in 1999 - A story of success!. 253 pb -1.

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News from ~1fb -1 of e + e - data at E cm =192-202 GeV

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  1. News from ~1fb-1 of e+e- dataat Ecm=192-202 GeV Nikos Konstantinidis UC Santa Cruz

  2. Outline • New physics in SM processes • photons, WW, ZZ… • Direct searches • Higgs and SUSY • The future • LEP at Y2K, after LEP? Nikos Konstantinidis - News from LEP

  3. LEP in 1999 - A story of success! 253 pb-1 Nikos Konstantinidis - News from LEP

  4. LEP operator: Not an easy job! <Fill time> Cryogenics operated at limit capacity! 2.7 hours RF cavities operated at ~<7 MV/m> well above their design gradient (~6MV/m) 2.1 hours 1.6 hours Nikos Konstantinidis - News from LEP

  5. For what follows... 30 pb-1 at 191.6 GeV 80 pb-1 at 195.5 GeV 85 pb-1 at 199.5 GeV 40 pb-1 at 201.6 GeV 235 pb-1/expt Results very preliminary!!! (presented one day after the end of run) open questions after the ADLO presentations implications of the latest results Emphasis on Limits at 95% C.L. - Discoveries at 5s Nikos Konstantinidis - News from LEP

  6. Final states with photons Topology SM process New processes Anomalous TGC’s Extra dimensions Single photon Single ISR Two acoplanar photons Double ISR SUSY (GMSB) Extra dimensions Excited leptons Contact interactions Two coplanar photons QED t-channel electron exchange Nikos Konstantinidis - News from LEP

  7. Results with photons Acoplanar photons Single photons 584 obs 592 exp 35 obs 34 exp Nikos Konstantinidis - News from LEP

  8. W/Z pair production Experimental precision challenges theory(*) Limits on anomalous neutral vector boson couplings and extra dimensions (*) hep-ph/9907436 hep-ph/9909363 Nikos Konstantinidis - News from LEP

  9. DELPHI eeqq excess mmqq Mqq~MZ eeqq Mqq (GeV/c2) Mll (GeV/c2) 10 observed / ~1 expected (in range 50-56 GeV/c2) Nikos Konstantinidis - News from LEP

  10. …not confirmed by others ALEPH llqq mass spectrum already studied before the DELPHI announcement: No excess! mmqq Specific modifications to approach the DELPHI analysis: Still no excess! eeqq 50-56 GeV/c2: 3.5 expected 1 observed Nikos Konstantinidis - News from LEP

  11. SM Higgs - A new regime e+ H Z* e_ Z New in 1999: - Moving away from MZ - Covering an exciting mass range Nikos Konstantinidis - News from LEP

  12. HZ - Topologies BR (%) 60 17 6 9 eff (%) 40 40 70 30 Bkg’s:ZZ,qq,WW ZZ,WW,qq ZZ,Zee ZZ,WW Handles:b-tagging Acoplanarity lepton-ID tau-ID 4 jet topol. Mmis = MZ + isolation b-tagging b-tagging Mll = MZ Nikos Konstantinidis - News from LEP

  13. ALEPH Higgs Rumors Jun Aug Shown to summer conferences Sep Rumors start here… Nov … and end here! Nikos Konstantinidis - News from LEP

  14. ALEPH Higgs Search Excess in data Cb max = 0.87 Data compatible with SM Deficit in data ~1 sigma excess Cb: The compatibility with SM background. Contains much more information than a mass plot! Nikos Konstantinidis - News from LEP

  15. SM Higgs results up to 202 GeV ADLO: ~109 GeV (~200 pb-1 only) (Up to 200 GeV only) Nikos Konstantinidis - News from LEP

  16. MSSM - Neutral Higgs bosons ADLO ‘99 Theory ‘99 ADLO: ~90 GeV Low tanb region slowly covered: ADLO: tanb > ~2 MSSM scans show no pathological points Beginning of LEP2 Nikos Konstantinidis - News from LEP

  17. Charged Higgs • Hitting the W wall • Enough luminosity to explore masses above MW (?) • OPAL + DELPHI excess around 90-95 GeV gone… ADLO (189 GeV): 77.3 GeV Nikos Konstantinidis - News from LEP

  18. SUSY topologies and backgrounds R-parity conserved: Missing energy + 4 jets 2 jets-lepton2 leptons 2 jets Signal event properties and backgrounds depend on: large DM small DM Nikos Konstantinidis - News from LEP

  19. Cross section limits Nikos Konstantinidis - News from LEP

  20. Covering the small DM region Nikos Konstantinidis - News from LEP

  21. The LSP mass limit From chargino kin. threshold Higgs searches may have a significant impact on the LSP mass limit! ~36 GeV Nikos Konstantinidis - News from LEP

  22. Other searches... • Invisible Higgs decays, fermiophobic Higgs • Squarks/sleptons, GMSB with stau as NLSP • Heavy stable particles • Excited leptons • Deviations from SM in 2-f processes • Anomalous TGC’s Nikos Konstantinidis - News from LEP

  23. LEP in Y2K - Ultimate reach 202 GeV : Successful operation in 1999 204 GeV : Pilot run (~10nb-1/expt) in 1999 206 GeV : Seems possible in 2000 (obtained in tests) 208 GeV : Optimistic? (but not out of question...) >210 GeV : forbidden by French law!!! • Standard Model Higgs Sensitive up to ~ (Ecm-MZ) -> 114 GeV/c2 • Charginos Sensitive up to ~ Ecm/2 -> 104 GeV/c2 • MSSM Higgs h,A close to 95 GeV/c2 charged Higgs: sensitivity above MW Nikos Konstantinidis - News from LEP

  24. If no Higgs at LEP? LEP’s last contribution to the Higgs search is the indirect determination of its mass using the most precise W mass to that date! “Ball” passed to Fermilab! If central value of MH stays as is now, strong motivation for both Tevatron and LHC to prepare for the most difficult Higgs hunt: MH ~ 130 GeV/c2 Nikos Konstantinidis - News from LEP

  25. Summary • 1999: a year of excitement and good results • … but negative results! An outstanding year for LEP concludes a decade of a successful experimental program of leading research!!! Not too late to reward it with a discovery!!! Nikos Konstantinidis - News from LEP

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