1. Axel Naumann, DØ University of Nijmegen, The Netherlands Status Of DØ

2. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 2 Overview Detector Data Luminosity DAQ Physics

3. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

4. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

5. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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 (ADC) p-side pulse height 1 mip ~ 25 counts Signal/Noise ~ 12 Layer efficiency ~ 97% Integrated Lumi (fb -1 ) 0.020.040.06 Layer 1,2 Bias Current Bias Current

6. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 6 p T (GeV) Significant improvement expected from alignment with data in near future Detector: Tracking Performance Survey-only alignment constants width = 36  m  (beam) = 30  m   = 20  m KS   +  – first SMT alignment - it helps!

7. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 7 Detector Calorimeter performance Run II High E T 3-jet event E T : 110, 240, 310 GeV E t miss : 8 GeV Liquid argon calorimeter with uranium absorber Channel Count: 99.9% J/   e + e -

8. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 8 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 Spec: 5 kHz 1000 Hz50 Hz tape Peak: 1.2 kHz 50 Hz 1000 Hz Level 2Level 1 Level 3 Operating: 0.7 kHz 50 Hz 300 Hz

9. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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*10 31 cm -2 sec -1, integrated lumi of 2fb -1 ; actual limit believed to be 2*10 32 cm -2 sec -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)

10. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

11. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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”)

12. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 12 DØ: Luminosity Luminosity vs. date 12/00 09/02 Tevatron delivered luminosity in the beginning below expectations; now catching up rapidly Reason why lumi is essential:

13. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 13 DØ: Luminosity Events vs. date 06/0109/02 Data taking efficiency was far below expectations; improved a lot, e.g. a run from last week: 93.5% 40 15 Dec 02

14. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

15. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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 2 nd biggest MC provider: 10 7 events 1/0212/02

16. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

17. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

18. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

19. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 19 Physics: Impact Parameter b Tag Jets with associated muon Courtesy of Bram Wijngaarden Generic jet sample Track Prim Vtx ImpP b quark

20. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 20 Data MC Pythia Physics: b Jet Cross Section Courtesy of Onne Peters  + jet cross section P T Rel for different samples b jet cross section from  + jet sample b    /K   c c  Run 2 data 20<E T Jet <25GeV Fit MC Pythia

21. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 21 Physics: Z  2  Candidate Courtesy of Silke Duensing Muon + narrow had jet, both with tracks Inv Mass  60GeV p  Z     + 2  

22. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 22 Top quark mass (GeV) W mass (GeV) 2001 m t  2 GeV m W  15 MeV Standard Model Supersymmetry Physics: Plans 2fb -1 –Measure top mass ±3 GeV –Measure W mass ± 15 MeV –Directly exclude m H = 115 GeV –SUSY Higgs search @ large tan  –Constrain the CKM matrix

23. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 23 6.5 fb -1 –3  Higgs signal @ m H = 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 m H = 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 @ m H = 115 GeV; –3  Higgs signal 115-175 GeV Physics: Plans Each factor of two in luminosity yields a significant increase in reach and lays the foundation for the next steps

24. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 24 DØ: Rumors… Breaking news: Higgs has been seen Strange properties: It’s not colorless! Cheaper than expected…

25. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

26. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 NIKHEF Annual Scientific Meeting 26 Detector: Forward Proton Elastic scattering data Scintillating fiber detector inside  t -59m+33m0m 0

27. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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

28. Axel Naumann, DØ University of Nijmegen, The Netherlands 19 Dec 2002 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)