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Status Of DØ

Status Of DØ. Overview. Detector Data Luminosity DAQ Physics. The DØ Detector. All elements in place! Commissioned: forward preshower FPS, forward proton detector FPD, level 1 central track trigger CTT Silicon track trigger STT under construction

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Status Of DØ

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  1. Status Of DØ

  2. Overview • Detector • Data • Luminosity • DAQ • Physics NIKHEF Annual Scientific Meeting

  3. The DØ Detector • All elements in place! • Commissioned: forward preshower FPS, forward proton detector FPD, level 1 central track trigger CTT • Silicon track trigger STT under construction • Fundamental change in DAQ: Switch to ethernet based DAQ very successful • Data taking efficiency >75% • >50pb-1 available for Moriond NIKHEF Annual Scientific Meeting

  4. The DØ Detector • New for RunII: • 2T solenoid • silicon tracker • Rebuilt • central tracking • part of calorimeter and muon system • trigger system NIKHEF Annual Scientific Meeting

  5. Detector: Silicon Tracker • Increase of bias current consistent with expectations, infers depletion voltage exceeds spec @ 4fb-1 p-side pulse height 1 mip ~ 25 counts Signal/Noise ~ 12 Layer efficiency ~ 97% Layer 1,2 Bias Current p-side pulse-height (ADC) Bias Current 0.02 0.04 0.06 Integrated Lumi (fb-1) NIKHEF Annual Scientific Meeting

  6. Detector: Tracking Performance width = 36 m (beam) = 30 m   = 20 m • KS  +– Survey-only alignment constants first SMTalignment - it helps! pT (GeV) Significant improvement expected from alignment with data in near future NIKHEF Annual Scientific Meeting

  7. Liquid argon calorimeterwith uranium absorber J/  e+e- Channel Count: 99.9% Run II High ET 3-jet eventET: 110, 240, 310 GeV Etmiss : 8 GeV Detector Calorimeter performance NIKHEF Annual Scientific Meeting

  8. 1000 Hz 50 Hz Spec: 5 kHz Level3 Level 1 Level 2 tape Peak: 1.2 kHz 1000 Hz 50 Hz Operating: 0.7 kHz 300 Hz 50 Hz Detector: Trigger, DAQ • L1: Cal, Muon available; CTT commissioning underway • L2: operating with CAL, Muon, Global; CTT, PS commissioning underway, STT expected to be operational spring 2003 (huge progress this year from prototype to production) • New ethernet based DAQ: Meets 1kHz L2 accept specs NIKHEF Annual Scientific Meeting

  9. Tevatron • Luminosity major concern: Tevatron and DØ DAQ performance in the beginning far below expectations (“got little beam and didn’t record events”) • Official lumi goal for RunIIa: >5*1031cm-2sec-1, integrated lumi of 2fb-1; actual limit believed to be 2*1032cm-2sec-1 • Main luminosity issues for DØ: • Tevatron delivered lumi: p-bar injection; helix tuning, cooling and losses; many more • DØ DAQ system: readout, triggers, event building etc (see above) NIKHEF Annual Scientific Meeting

  10. Tevatron • Every performance improvement evident in the luminosity performance plot has been associated with a specific modification to the accelerator complex. • Major modifications since January 1, 2002: • Accumulator->Main Injector transfer optics • Adjustment of tunes during low beta squeeze • Modified injection helix in Tevatron • Proton beam loading compensation in Main Injector • Accumulator (stochastic) cooling upgrade • Accumulator shot lattice • Antiproton beam loading compensation in Main Injector • Tevatron beam line tuner (BLT) • Tevatron tune/coupling drift compensation • Tevatron transverse dampers • Beams division guy: (1.15)10 =4.0 NIKHEF Annual Scientific Meeting

  11. Tevatron: Plans • January 3.5 week + summer shutdown used for maintenance and improvements RunIIb prospects: R&D still going on, official “baselining” in a few days (“DØ’s Christmas present”) NIKHEF Annual Scientific Meeting

  12. Luminosity vs. date 12/00 09/02 DØ: Luminosity Tevatron delivered luminosity in the beginning below expectations; now catching up rapidly Reason why lumi is essential: NIKHEF Annual Scientific Meeting

  13. DØ: Luminosity Data taking efficiency was far below expectations; improved a lot, e.g. a run from last week: 93.5% Events vs. date 40 06/01 09/02 15 Dec 02 NIKHEF Annual Scientific Meeting

  14. DØ: RunIIb Detector Plans • New silicon detector: • Single sided, barrels only • Installation takes 7 weeks (starting beginning of 2005) • Inner (vertexing) layers 0, 1 axial, on carbon support • Outer (tracking) layers 2-5 axial + stereo (tilted sensors) • Prototype module essentially done • Lots of experience from RunIIa silicon NIKHEF Annual Scientific Meeting

  15. Physics: Analysis • Updated reconstruction software: Improved tracking efficiency, object identification, jet energy correction etc • Reconstruction farms in place for high luminosity • NIKHEF 2ndbiggest MC provider: 107 events 1/02 12/02 NIKHEF Annual Scientific Meeting

  16. Physics: Analysis • Remote analysis possible, e.g. @ Amsterdam, Nijmegen: • running local code installations, provided by standard code distribution system • retrieving data from all other centers (which is, 99%, FNAL) transparently by “SAM” • huge improvement to last year’s “500 users on one machine” situation NIKHEF Annual Scientific Meeting

  17. Physics: Analysis Strategy • Topics of interest for NIKHEF: top, Higgs • Until there is enough luminosity: bread and butter physics, developing and using tools • b jet tagging (leptons, lifetime, vertex), cross section • Z  b b (benchmark for Higgs search), cross section • Already now first top analyses: • cross section t t  all hadronic and t t  e + jets NIKHEF Annual Scientific Meeting

  18. Physics: Analysis Topics • NIKHEF PhD students’ work (physics!) at DØ • Silke Duensing:  ID (see the so far unseen at DØ) • Paul Balm: exclusive b decay • Bram Wijngaarden: b jet search with lifetime information • Onne Peters: b jet cross section measurement • Axel Naumann: Z  b b cross section measurement • Freya Blekman: tt  all hadronic • Lukas Phaf: tt  e +  + jets • Cristina Galea NIKHEF Annual Scientific Meeting

  19. Physics: Impact Parameter b Tag Track ImpP b quark Prim Vtx Jets with associated muon Generic jet sample Courtesy of Bram Wijngaarden NIKHEF Annual Scientific Meeting

  20. Data MC Pythia Physics: b Jet Cross Section b jet cross section from  + jet sample PTRel for different samples Run 2 data 20<ETJet<25GeV Fit b  MC Pythia /K   + jet cross section c Courtesy of Onne Peters NIKHEF Annual Scientific Meeting

  21. Physics: Z 2 Candidate Muon + narrow had jet, both with tracks Inv Mass  60GeV Courtesy of Silke Duensing NIKHEF Annual Scientific Meeting

  22. 2001 W mass (GeV) mt 2 GeV mW  15 MeV Supersymmetry Standard Model Top quark mass (GeV) Physics: Plans • 2fb-1 • Measure top mass ±3 GeV • Measure W mass ± 15 MeV • Directly exclude mH = 115 GeV • SUSY Higgs search @ large tan  • Constrain the CKM matrix NIKHEF Annual Scientific Meeting

  23. Physics: Plans • 6.5 fb-1 • 3 Higgs signal @ mH = 115 GeV; • exclude Higgs 115-125, 155-175 GeV • exclude much of SUSY Higgs parameter space • possible discovery of SUSY in very large fraction of minimal SUSY parameter space • 11 fb-1 • 3 Higgs signal mH = 115-125, 155-175 GeV; • exclude Higgs over whole range 115-175 GeV • possible discovery of SUSY in larger fraction of parameter space • 15 fb-1 • 5 Higgs signal @ mH = 115 GeV; • 3 Higgs signal 115-175 GeV Each factor of two in luminosity yields a significant increase in reach and lays the foundation for the next steps NIKHEF Annual Scientific Meeting

  24. DØ: Rumors… • Breaking news: Higgs has been seen • Strange properties: It’s not colorless! • Cheaper than expected… NIKHEF Annual Scientific Meeting

  25. DØ: Summary And Future • Detector completed, running smoothly • Luminosity excellent progress in the past year that serves as a solid platform for future progress • First “real” physics results are coming in • Main area of work now reconstruction, analysis NIKHEF Annual Scientific Meeting

  26. Detector: Forward Proton Elastic scattering data x 0 t Scintillating fiber detector inside -59m 0m +33m NIKHEF Annual Scientific Meeting

  27. Detector: Forward Preshower Extensive forward coverage: 1.5  || 2.5 u,v stereo layers with 15k channels Offline reconstruction using matched u, v clusters and E correlation NIKHEF Annual Scientific Meeting

  28. Detector: Scintillating Fiber Tracker • Fully instrumented, performing well (layer eff >98%)Also used for track triggering on Level 1 (CTT) NIKHEF Annual Scientific Meeting

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