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Unveiling the Higgs Mystery with DØ: From Now to the Future

Follow the sweeping achievements and wild predictions of the DØ experiment at the Tevatron, navigating through the realm of high-energy physics. Take a dive into fundamental forces, bosons, and fermions to uncover the mysteries beyond the Standard Model. Discover the quest for the elusive Higgs particle as Run II commences with fervor. Delve into the complexities of quantum fields and diverse phenomena, exploring the intricate tapestry of particle interactions. Join the scientific pursuit to untangle the enigmatic truths of the universe, from EW Symmetry Breaking to Quark Weak States and more.

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Unveiling the Higgs Mystery with DØ: From Now to the Future

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  1. The DØ Experiment now and later… Hal Evans Columbia University • Sweeping Generalizations (broad goals of HEP) • Experimental Specifics (the Tevatron & DØ) • Wild Predictions (Run II Physics at DØ) Run II has started! We haven’t seen the Higgs yet Cornell Colloquium - 30 April, 2001

  2. Fundamental Forces: Bosons Point-Like Particles: Fermions What do We Know? Cornell Colloquium - 30 April, 2001

  3. What’s it all about? The broad goal of HEP • measure something at odds w/ an SM prediction • hints of what lies beyond If it ain’t broke – fix it! • Has 19 arbitrary parameters • Higgs Mass not stable to radiative corrections •  ~ Mplanck for no new physics • Mh < 800 GeV  tuning to 10-16 • Why’s? of EW Symmetry Breaking • What about Gravity? • Why Mpl(1018GeV)»MEW(250GeV)? Cornell Colloquium - 30 April, 2001

  4. Where do we look? Concentrate on areas where • we don’t have complete understanding • measurements are few • EW Symmetry Breaking Higgs in SM • direct searches for Higgs / new particles • need highest possible energy (or lowest) • precision measurements of EW param’s • sensitivity to H.O. effects from Higgs/New Phys • effects in rare processes • New Phys couples to mass  t-,b-decays • Quark Weak vs. Mass Eigenstates CKM Matrix in SM • Mixing, CP Violation,… • B0, K0 decays • Lepton Weak vs. Mass Eigenstates same in SM • neutrino mass, mixing & CP • Strong Interactions QCD in SM • Perturbative vs. Non-perturb. Cornell Colloquium - 30 April, 2001

  5. Stalking the Higgs LEP EW-WG: hep-ex/0103048 Cornell Colloquium - 30 April, 2001

  6. Quark Weak  Mass Eigenstates CKM Mixing Matrix Independent param’s 3 angles 1 complex phase  CP-viol CP violation obs. in K0, B0 systs Unitarity of VCKM 12 eqn’s the Unitarity Triangle is one Quarks are all mixed up ! (,)    (0,0) (0,1) Cornell Colloquium - 30 April, 2001

  7. How to Build a Triangle Cornell Colloquium - 30 April, 2001

  8. Leptons too? Mixing formalism is possible for leptons • 2-flavor mixing is simplest Oscillation Probability • Posc = sin22 sin2(1.27m2L/E) • m2 = m12 – m22 Note:  = 0 in the SM Cornell Colloquium - 30 April, 2001

  9. There are lots of Ideas… Dynamical Symmetry Breaking Technicolor: running, walking, limping… Supersymmetry (SUSY) GMSSM, SUGRA, R-Parity Violating Large Extra Dimensions testable string theory! etc., etc., etc… They all answer some questions They all look like the SM at low E Differences only show up at high Energy small corrections to SM predictions 2 Strategies: Look Harder Precision Bigger Hammer Energy Some Guidance ? Cornell Colloquium - 30 April, 2001

  10. Higgs Mass problem can be solved by adding a Superpartner for every SM particle and 5 Higgs: h0, H0, A0, H± Usually require R-Parity Conserv LSP is stable (often ) Note: SUSY is a broken at low-E M(susy ptcl’s)  M(SM ptcl’s) Simplest SUSY models require Mh < 135 GeV (!!!) If you knew SUSY... Cornell Colloquium - 30 April, 2001

  11. UnderlyingEvent g q u u q d u d u Hard Scatter Collisions at the Tevatron p Collisions  qq(g) Interact’s • Fermilab Tevatron: • Circumference ~ 4 mi. • 20’ underground • 1000 super-conducting magnets Cornell Colloquium - 30 April, 2001

  12. The Times – they are a changin’ Major upgrade to the Tevatron • main injector • antiproton recycler Cornell Colloquium - 30 April, 2001

  13. DØ Collaboration >500 People 17 Countries Cornell Colloquium - 30 April, 2001

  14. DØ Run II Upgrade Forward Scint Central Scintillator Forward Mini-drift chamb’s Central PDTs Shielding Calorimeter Tracking: Solenoid,Silicon,Fiber Tracker,Preshowers New Electronics,Trigger,DAQ Cornell Colloquium - 30 April, 2001

  15. Status all detectors installed reading out ~25% cabling/checkout ~all by mid May tracks seen! • 6 Barrels • 12 F-Disks • 4 H-Disks 12 11 10 9 6 5 4 4 3 2 3 1 2 1 8 7 6 5 Silicon • 793k Channels • 3.0 m2 Si (1.6 m2 D.S.) • SVX IIe Readout • L2 Trigger (’02) Cornell Colloquium - 30 April, 2001

  16. Silicon Pictures Cornell Colloquium - 30 April, 2001

  17. Scint Fibers (830 m) 8 dbl Cylinders Axial & (±3o) Radii: 20 – 51 cm Active Lengths: 1.66 m (inner-2) 2.52 m (outer 6) VLPC Readout: ~77k Channels SIFT + SVX IIe L1 Trigger Info Status detector & w’guides installed reading out ~5% electronics in prod install electr over summer Fiber Tracker Silicon Solenoid Central Fiber Tracker Central Preshower Forward Preshower Cornell Colloquium - 30 April, 2001

  18. Fiber Tracker Pictures Cornell Colloquium - 30 April, 2001

  19. Status Central & Forward installed waiting for electronics (CFT) some noise issues in trigger Preshowers Central Calorimeter Central PS Solenoid Tracking Calorimeters Forward Forward PS Solenoid Tracking Cornell Colloquium - 30 April, 2001

  20. Forward PS Installed Cornell Colloquium - 30 April, 2001

  21. Detector Unchanged from Run I (U-LAr) New Electronics to cope with BX frequency Status reading out entire calorimeter waiting for final electronics mainly effects forward trigger New Calibration Tools Zbb (b-jet scale) Peak pos to 0.3% Requires STT E/P new track Pt meas. E/P Electrons Calorimeters Cornell Colloquium - 30 April, 2001

  22. Replace Forward System MDTs + Scint Pixels Add Scint’s in Central improved triggering PDTs from Run I remain Improve Beam Shielding Remake Trigger System Status all detector elem’s installed signals seen! ramping up triggers Muon System Trigger Scint (A-) Scint Pixels Toroids MDTs (Iarocci) PDTs(Run I) Shielding Bottom B/C Scint Cornell Colloquium - 30 April, 2001

  23. A-Layer Forward Pixels Cornell Colloquium - 30 April, 2001

  24. Other Systems Luminosity Monitor • operational Forward Proton Detector • improve DØ diffraction measurements • series of Roman Pots outside of quad’s ICD & Massless Gaps • fill cracks in calorimeter • electronics in production Cornell Colloquium - 30 April, 2001

  25. Conclusion: too much Physics! Trigger Happy 7 MHz • Single Sub-Det’s • Towers, Tracks, ET-miss • Some correl’s • Not deadtimeless L14.2 s(128 terms) F’work 10 kHz • Correlations • Calibrated Data • Physics Objects e,,j,,ET-miss L2100 s(128 terms) 1 kHz Data L350 ms(48 nodes) • Simple Reco • Physics Algo’s 50 Hz * M(H) = 100 GeV Cornell Colloquium - 30 April, 2001

  26. Status Level 1 basic triggers available driven by CFT electronics Level 2 electronics in production expect first triggers in June Level 3 running at reduced rate SBs redesigned & in prod FE FE FE FE FE FE FE FE SB 1 SB 4 Node Node Node Node DØ Trigger & DAQ Detector Level 1 Level 2 Level 3 & DAQ 7 Mhz 10 khz 1 khz Token rdout loop CAL L1Cal L2Cal VRC 1 VRC 8 c/f PS L1PS L2PS CFT L1CTT L2CTT SMT L2STT L1Mu evt tag loop MU L2Mu EvtTagGen FPD L1FPD L1,L2 Info Global L2 ethernet Lumi Framework Cornell Colloquium - 30 April, 2001

  27. Here it is! Cornell Colloquium - 30 April, 2001

  28. Detector Performance Cornell Colloquium - 30 April, 2001

  29. The Run II Game Plan Cornell Colloquium - 30 April, 2001

  30. Physics Galore! • Run II Tevatron Working Groups • http://www-theory.fnal.gov • Publications • Higgs hep-ph/0010338 • SUGRA hep-ph/0003154 • BTMSSM hep-ph/0006162 • RPV hep-ph/9906224 • GM SUSY hep-ph/0008070 • Electroweak Fermilab-PUB-00/297 • Top see web (above) • B see web (above) Cornell Colloquium - 30 April, 2001

  31. Background Properties Low ET Jets ET Balanced No High PT Leptons No Displaced Vertices QCD is IT Cornell Colloquium - 30 April, 2001

  32. Properties High ET Jet High PT Lepton Missing Energy Backgrounds QCD Instrumental (miss-meas.) Vector Bosons jet Cornell Colloquium - 30 April, 2001

  33. Properties High ET Jets Displaced Vertices Soft Leptons (b) High PT Leptons Missing Energy Backgrounds W/Z + jets WW, ZZ, WZ QCD + miss-meas. Top Production jet jet Cornell Colloquium - 30 April, 2001

  34. Properties Displaced Vertices Soft Leptons (b) Backgrounds QCD Other B-decays B Production Cornell Colloquium - 30 April, 2001

  35. Properties High ET Jets Displaced Vertices Soft Leptons (b) High PT Leptons Missing Energy Backgrounds W/Z + jets WW, ZZ, WZ Top QCD + miss-meas. Higgs Cornell Colloquium - 30 April, 2001

  36. SM Higgs at the Tevatron Representative Cross-Sections (s = 2.0 TeV) Moral: Use WH / ZH Production Cornell Colloquium - 30 April, 2001

  37. Properties High ET Jets Displaced Vertices Soft Leptons (b) High PT Leptons Missing Energy Backgrounds W/Z + jets WW, ZZ, WZ Top QCD + miss-meas. Expect the Unexpected jet jet Cornell Colloquium - 30 April, 2001

  38. Recognizing Physics Cornell Colloquium - 30 April, 2001

  39. Precision Also watch for • W X-sect  Luminosity measurement • tWb / t Wq • tt Spin correlations • top Yukawa (ttH) • top – anti-top resonances Cornell Colloquium - 30 April, 2001

  40. Top Mass Errors W Mass Errors Most scale with luminosity What may not PDFs(): 7 MeV Run I Pt(W): 15 MeV Run I Precision EW Tests Run II proj Cornell Colloquium - 30 April, 2001

  41. Beauty Also watch for • b Production x-section & correlations • Bs Ds K, J/ , … • Bd mixing • B-hadron properties: lifetimes, spectroscopy, polarization • Onia Cornell Colloquium - 30 April, 2001

  42. DØ Assumptions: S/B ~ 0.75 Time res: t ~ 100 fs -  + b  -  - b + sin2 at DØ Cornell Colloquium - 30 April, 2001

  43. BJ/Ks Reconstruction • J/+- • 2 Muons: ||<2.0, PT>1.5GeV • Ks+- • Long lifetime rejects bgrd • Lxy/ > 5 • 4-Track Constrained Fit • mass: J/, Ks • vertex: KsB, B primary • unconstr: •  = 41 MeV <Lxy> = 2.3 mm • constr: •  = 10 MeV res = 100 m Cornell Colloquium - 30 April, 2001

  44. Searching Also watch for (list limited by imagination) • SUSY particle zoo • Technicolor • Your favorite Beyond the SM theory Cornell Colloquium - 30 April, 2001

  45. Key AreasImprove bb Mass Resolution 30% b-tagging Eff 80% Backgrounds bb Higgs Searches Cornell Colloquium - 30 April, 2001

  46. b-Quarks and the Higgs S/B vs Mbb S/B vs  b-tag Cornell Colloquium - 30 April, 2001

  47. Higgs at the LHC Cornell Colloquium - 30 April, 2001

  48. Beyond the SM – MSSM Tevatron Cornell Colloquium - 30 April, 2001

  49. Conclusions • Run II has started • Expect luminosity after May shutdown • Stable running after September • Run IIb  >15 fb-1 before LHC • DØ is ramping up • Finish instrumenting detector over summer • Full capability after September shutdown Cornell Colloquium - 30 April, 2001

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