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D Ø at Run IIa as the new B-Physics/charmonium player

D Ø at Run IIa as the new B-Physics/charmonium player. Heriberto Castilla Cinvestav-IPN Dzero Collaboration Workshop on Quarkonium November 8-10, 2002 at CERN. Run 1b. Run 2a. Run 2b. Bunches in Turn. 6  6. 36  36. 140  103. s (TeV). 1.8. 1.96. 1.96.

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D Ø at Run IIa as the new B-Physics/charmonium player

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  1. DØ at Run IIa as the new B-Physics/charmonium player Heriberto Castilla Cinvestav-IPN Dzero Collaboration Workshop on Quarkonium November 8-10, 2002 at CERN Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  2. Run 1b Run 2a Run 2b Bunches in Turn 6  6 36  36 140 103 s (TeV) 1.8 1.96 1.96 Typical L (cm-2s-1) 1.6 1030 8.6 1031 5.2 1032  Ldt (pb-1/week) 3.2 17.3 105 Bunch xing (ns) 3500 396 132 Interactions / xing 2.5 2.3 4.8 Run 1Run 2a Run 2b 0.1 fb-1 24 fb-115 fb-1 Physics Challenges  The Upgraded Tevatron Physics goals for Run 2 • precision studies of weak bosons, top, QCD, B-physics • searches for Higgs, supersymmetry, extra dimensions, other new phenomena require • electron, muon, and tau identification • jets and missing transverse energy • flavor tagging through displaced vertices and leptons • luminosity, luminosity, luminosity… Peak Lum. achieved over 3.5 1031 cm2s1 Planned to reach Run 2a design by Spring 2003 Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  3. Tevatron Luminosity Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  4. The Run II DØ Detector Calorimeters Tracker Muon System protons Beamline Shielding 20 m Electronics antiprotons Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  5. DØ in RunII • Center of Mass Energy = 1.96 TeV • Expect 2 fb-1 by end of 2004 (RunIIa), 15 fb-1 by 2008 (RunIIb) • Goals • B Physics ( B lifetime, B mixing, exclusive decays) • J/ and  production properties (polarization vs pT) • Comprehensive study of top quark properties • Precise measurements of mtop, mW • Search for new phenomena (SUSY, technicolor,…) • Search for the Higgs boson • QCD (proton structure, quark compositeness) • DØ’s strength is high-pT Physics but we can also do low-pT Physics • Requires • Measurement of leptons (e, ), jets, missing pT • Flavor tagging of jets Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  6. DØ Tracker 125 cm Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  7. Silicon Microstrip Tracker (SMT) 12 F Disks 4-layer barrel cross-section 4 H Disks 6 Barrels Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  8. pT dependent impact parameter resolution at vertex is 100 m using SMT only tracks and improves to  48 m when CFT data is combined with SMT data--and is expected to improve further as studies progress y track x Tracking Performance Ks +- Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  9. Forward Trigger Scintillators PDTs A- Scint Shielding Forward Tracker (MDTs) Bottom B/C Scintillators Muon System • Central and Forward regions, coverage up to  = ± 2 • Three layers: one inside (A), two outside (B, C) the toroid magnets • Consists of scintillators and drift tubes • Central Proportional Drift Tubes (PDT’s) • 6624 drift cells (10.1  5.5 cm) in 94 three- and four-deck chambers • Central Scintillation Counters • 360 “cosmic ray” counters outside the toroid ( = 22.5) • 630 “A” counters inside ( = 4.5),  = 0.1 • Forward Mini Drift Tubes (MDT’s) • 6080 8-cell tubes in 8 octants per layer on North and South side, cell cross-section 9.4  9.4 mm • Forward Scintillation Counters (Pixels) • 4214 counters on the North and South side •  = 4.5 matches the MDT sector size Fully commissioned Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  10. Muon System Muon Trigger Counters DØ Detector in Collision Hall, January 2001 Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  11. M = 3.08  0.04 GeV  = 0.78  0.08 GeV Muon System Performance Muon Timing ’s from Collisions Cosmic rays Timing cuts reduce cosmic bckg., could aid in detection of slow moving particles Matching of central tracks to ’s improves momentum resolution J/ invariant mass Muon stand alone system Muon plus central tracking Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla CHEP02 – 31st International Conference on High Energy Physics, Amsterdam, 24 – 31 July, 2002

  12. Decision times: ~4.2 s ~100 s ~50 ms L3 Trigger 1 kHz 2.3 (7.5) MHz 50 Hz 5 kHz Tape L3/DAQ DØ Trigger System Level 1 • Subdetectors • Towers, tracks, clusters, ET • Some correlations • Pipelined Level 2 • Correlations • Calibrated Data • Separated vertex • Physics Objects e, , j, , ET Level 3 • Simple Reconstruction • Physics Algorithms • Entire Trigger Menu configurable and downloadable at Run start • Trigger Meisters provide trigger lists for the experiment by collecting trigger requests from all physics groups in the Trigger Board • All past and present trigger lists are stored and maintained in the dedicated trigger database Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  13. DØ Beauty/Charmonium Physics Program • J/ψ cross section and polarization • Y cross section • B Lifetimes • Average B lifetime: b J/X • b lifetime: bJ/0 • B0s lifetime and width: B0sJ/ • CP violation, sin(2): B0J/ K0s • B0s mixing: BsDs l X, BsDs(n) • Rare decays, cross sections Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  14. Run II J/ production cross section 4.8 pb-1 of data ~30% systematic uncertainty region not measured in Run I Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  15. Future measurements: J/ polarization θ = angle(J/ψlab,μJ/ψ) I(θ) = 3/2/(α+3) (1+ α cos2 θ) α = (σT -2σL)/(σT +2σL) pt(J/ψ) > 10 |η(J/ψ)| < 1.8 pt(μ) > 2 η(μ)| < 1.9 Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  16.   +-in DØ • pT of tracks > 2 GeV Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  17. Average B Hadron Lifetime • 416 ± 30 signal events • 2184 ± 47 prompt J/’s • (B) = 492 ± 37 m (PDG: (B) = 469 m) • Same sample as B± J/K± • pT(J/)>4 GeV/c Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  18. DØ’s First B Hadron Candidates • ~5 pb-1 • J/ vertex • pT(track)>2 GeV/c, matched to a muon • Positive decay length • pT(K)>0.5 GeV/c • B vertex • pT(B)>10 GeV/c • 2<10 • Decay length>120 m • Colinearity angle (pl)>0.9 Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

  19. Conclusion • First physics results at 1.96 TeV • J/ studies • J/ cross section (cross checks with Run I measurement) • Average B Lifetime consistent with previous measurements • First observation in D0 of a charged B • Tools to work on quarkonium • Prompt J/ (’) and from Bs • Upsilon • Polarization measurements •  radiative decays • Improvements in store: • CTT and STT triggers soon • Increased rate of J/ and  to tape Workshop on Quarkonium, November 8-10, 2002 at CERN Heriberto Castilla

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