1 / 26

Diffraction in Run I New Detectors for Run II Diffractive dijets: Q 2 dependence

Diffractive Physics at CDF II: diffractive structure function. Michele Gallinaro – The Rockefeller University (for the CDF collaboration) Small- x and Diffraction, Fermilab. Diffraction in Run I New Detectors for Run II Diffractive dijets: Q 2 dependence. Diffraction in Run I.

csilla
Download Presentation

Diffraction in Run I New Detectors for Run II Diffractive dijets: Q 2 dependence

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Diffractive Physics at CDF II: diffractive structure function Michele Gallinaro – The Rockefeller University (for the CDF collaboration) Small-x and Diffraction, Fermilab • Diffraction in Run I • New Detectors for Run II • Diffractive dijets: Q2 dependence

  2. Diffraction in Run I • Large rapidity gaps are signatures for diffraction • Soft diffraction • SD • DD • DPE • multi-Gap control sample • Hard diffraction • SD (W, jet-jet, b-quark, J/y) • SD (w/RP) dijets (630 GeV and 1.8 TeV) • Forward jets (Jet-Gap-Jet) • DPE dijets SD dijets Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  3. If you want to know more… for a review: hep-ph/0306085 …see Goulianos’ talk tomorrow ! Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  4. First Goals for Run II • Diffractive structure function  Q2 and x dependence • Exclusive production  dijet, heavy flavor, low-mass Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  5. Chicago  Booster CDF DØ Tevatron p source Main Injector (new) Tevatron Collider • Tevatron and detector upgrades • C.M. energy 1.96 TeV • 396 nsec bunch spacing • high (low ?) inst. luminosity • (L ~ 2-3 x 1031 cm-2sec-1) • multiple interactions Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  6. New Detectors for Run II time-of-flight tracker • Tracking • Silicon • Central Outer Tracker • Time of Flight • Expanded Muon Coverage • Endplug Calorimeter • Forward Detectors • Trigger • Tracks @ L1 • Silicon Tracks @ L2 • DAQ (132 ns) MiniPlug calorimeter Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  7. Forward Detectors • Roman Pots Spectrometer • Beam Shower Counters • MiniPlug Calorimeter  Larger h coverage for rapidity gaps and jets Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  8. Beam Shower Counters L1 Trigger Beam Losses Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  9. Roman Pot Spectrometer Fiber Tracker • 3 stations • 57 meters from IP • 3 trigger counters • 240 channels MIPs ( >1000 counts) Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  10. New MiniPlug Calorimeter • liquid scintillator + lead • towerless geometry • full coverage: 3.5< || < 5.1 Measure: very forward jet energies and position multiplicity Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  11. MiniPlug Design East MP (viewed from IP) Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  12. Path to diffractive results • 2) Data • triggers are prescaled • more than 100 pb-1 collected • 1) Detectors • installed (MP/November 2001) • triggers implemented • fully instrumented • ready in September 2002 • 3) Results • what do we find? (what do you see?) • next Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  13. Diffractive Dijets x: fraction of anti-proton momentum loss b: fraction of pomeron momentum carried by parton parton xBj  b . x (LO QCD) • CDF Run I result suppressed • by a factor of ~10 relative to HERA • breakdown of QCD factorization (renormalization removes s-dependence) • K. Goulianos, PLB 358 (1995) 379 Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  14. Trigger • RP is triggered on leading antiprotons • Use RP + jet triggers require jets Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  15. Event Samples Dedicated triggers  total rate ~3Hz Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  16. x : Momentum Loss Fraction Measure fractional momentum loss of anti-proton MX 2 x = s S ETe-h  x = s Dy= ln (1/x) Diffractive events are boosted towards positive h  small x Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  17. Single Diffractive Dijets • Compare diffractive events to ND • Measure diffractive structure function • from RSD/NDvsx Bj overlap events Measure x ( p momentum loss fraction) from calorimeter information Approx. flat at x<0.1 constant Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  18. SD: Event Selection Data presented from 8 pb-1: • RP acceptance ~80% (from Run I) • negligible (< 1-2%) RP background trigger Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  19. Kinematic Properties Compare ND and SD Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  20. Ratio of SD/ND Events Sjet ET e-h xBj= s (jet=1,2,3 if ET>5 GeV) • slope and normalization agree with Run I result • work in progress to evaluate ratio at smaller x values Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  21. Q2 dependence ET1+ ET2 ET* = 2 • select energy intervals • overall norm. only • no significant Q2 dependence Pomeron evolves similarly to proton (?) Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  22. Summary • CDF forward detectors working well • dedicated diffractive triggers • re-established Run I measurements • no significant Q2 dependence in SD/ND ratio Run II analyses are well underway ! Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  23. More CDF Run II results in the following talks… Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  24. Backup Slides …TO FOLLOW… Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  25. MP Calibration • Use slope from ADC distribution • Tower-to-tower relative calibration with data/MC • Energy scale from MC • MC/MBR • Pile-up at high luminosity • (Slope-Fit)/Fit ~7% for each  ring • Time dependence (LED) Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

  26. DPE Dijet Production from SD data: DPE SD SD: proton side SD: anti-proton side Michele Gallinaro, "Diffractive Results at CDF II" - Small-x and Diffraction, Fermilab, Sept. 17-20, 2003

More Related