1. d u +-Strom I wk + u d --Strom I wk - d(u) u(d) 3-Strom I wk 3 W-W- W+W+ W3W3 n p +-Strom + p n --Strom - n(p) p(n) 3-Strom 3 - + 0 Parallele starker-schwacher Isospin: Folgerung GIM: Wenn schwache WW sich als SU(2) beschreiben laesst, dann muss es auch neutrale Stroeme geben!

4. CDF and DØ in Run II New Silicon Detector New Central Drift Chamber New End Plug Calorimetry Extended muon coverage New electronics Silicon Detector 2 T solenoid and central fiber tracker Substantially upgraded muon system New electronics Driven by physics goals detectors are becoming similar: silicon, central magnetic field, hermetic calorimetry and muon systems ØDØØDØCDF

5. Top Quark Production and Decays Top quarks at Tevatron are (mainly) produced in pairs via strong interaction Top pair cross section at 1.96 TeV is 6.7 pb In SM top decays 100% to Wb Classification of top decays is based on W s decays % e qq e 1.22.5 14.8 1.22.514.8 1.214.8 qq44.4 classification: di-lepton, lepton+jets, all jets Two b quarks in final state!!! 85% 15%

7. Detection of High P t Objects Electrons Missing E t Muons Top and Higgs final decay products electrons muons jets (b) missing E t ( ) Detection and MC optimization using well known objects

9. Selection of Top Quark Events In triggering and analysis select events with high P t leptons high E t multiple jets large missing E t ( ) displaced vertex for b jets Di-lepton mode has low backgrounds: di-bosons, Drell-Yan,... but low statistics: ~5% for e, decays Lepton+jets very productive mode 6 times more decays then di-lepton mode main background W+jets good purity after b tagging All jets mode ~50% branching high QCD backgrounds, jets combinatoric

13. Run II Top Mass at CDF di-leptons l+jets, b tagged l+jets … erst gut durch Kombination vieler einzelner Analysen

14. Run II Top Quark Cross Section Measurements demonstrate success of multiple top detection techniques Results within errors consistent with NNLO SM predictions for 1.96TeV of 6.7pb

15. Tevatron Top Quark Mass m t = 178.0 4.3 GeV Run II top quark mass results from both detectors are available Ø TeV EWWG is working on combining Run II top mass measurement from CDF and DØ Systematic error (mainly jet energy scale) is becoming limiting accuracy factor

18. Resonances in tt system? M X > 560 GeV No resonance production in tt system is expected in SM Some models predict tt bound states, example: topcolor-assisted technicolor predicts leptophobic Z with strong 3 rd generation coupling Experimental check: search for bumps in tt effective mass spectrum Ø, 125 pb -1 DØ, 125 pb -1 Background Top Total