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Task A: ZEUS 2006-2007

Task A: ZEUS 2006-2007. N. Brummer, L.S. Durkin, T.Y. Ling. O.S.U. History on ZEUS. Joined ZEUS 1985 One of U.S. ZEUS founding members. Designed and Built Optics for ZEUS Barrel Calorimeter. 87,000 Scintillator Tiles 5000 Wavelength-Shifter Light Guides and

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Task A: ZEUS 2006-2007

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  1. Task A: ZEUS 2006-2007 N. Brummer, L.S. Durkin, T.Y. Ling

  2. O.S.U. History on ZEUS Joined ZEUS 1985 One of U.S. ZEUS founding members Designed and Built Optics for ZEUS Barrel Calorimeter 87,000 Scintillator Tiles 5000 Wavelength-Shifter Light Guides and Correction Masks Designed and Built FastClear Trigger Processor Fast (15sec) Cluster Finder Electron Identification Kinematic Variables E-PZ Beam Gas Rejection Manufactured Optics for Barrel Calorimeter Presampler

  3. Group History on ZEUS (cont.) Administrative U.S. ZEUS Spokesman 3 Physics Coordinators Run Coordinator Trigger Coordinator Post-Doctoral Fellows B. Bylsma,C.L.Kim, C. Ginsburg, N.Brummer K. McLean, B. Murray, S. Park, I. Park, D. Acosta Physics Chair Assoc. Prof. Assoc. Prof. Korea U. Kyungpook U. U. of Florida 3 faculty Positions out of 9 postdocs !

  4. Background Problems fixed ! • Synchrotron radiation fixed • e-gas decreased • p-gas decreased HERA I (8 years) 193 pb-1 HERA II (2.5 years) 403 pb-1 • New Data has Polarized Electron/Positrons • 4X increase in e-p Data

  5. Rate Increase: Fast Clear is now an Essential Component • Fast Calorimeter Cluster • Finding Trigger • E-Pz,PT, Beam Gas, Electron • Clusters, Jet Clusters • Abort fraction 20-30% • WWW run monitor written • Trigger works stably • Better Modeled in MC than • CFLT

  6. HERA Kinematics 30 GeV e± 900 GeV p C.M. 315 GeV centre-of-mass energy squared: s = (k + p)2 = 4 Ee Ep Q2 = -q2 = - (k – k‘)2 = s x y four-momentum transfer x = Q2 / (2Pq) Bjorken-x momentum fraction of struck parton y = (Pq)/(Pk) Inelasticity relative energy transfer to the proton

  7. Physics with a Polarized Electron Beam Standard Model Neutral Current left/right handed particles interact unequally with Z0 Charged Current left-handed particles only HERA Transverse Polarization builds up naturally at HERA (Sokolov-Ternov effect) at HERA =30min Paverage=40% (depol. effects) The Cross section depends on polarization. One Searches for e.g. WR and tests Standard model. With one years data should be able to set limit MW(R) < 400 GeV

  8. Charge Current Cross Section

  9. Charge Current Deep Inelastic Scattering

  10. HERA will shutdown forever June 30, 2007 FLMeasurement HERA plans to run low-energy collision in 2007 460 GeV p 27.5 GeV e Naïve Quark Model: Hadrons quarks have P(T)=0 QCD radiation introduces quark P(T) Theoretical Predictions Vary Wildly

  11. In July we sent a note resigning from the ZEUS Collaboration Effective December 2006 • Decision a Finacial one, we did not have the funds • to support Nichol Brummer. • Collaboration begged us to stay on. The OSU Fast Clear • essential to low energy run (rejects 30% of background). • We agreed to stay on if one-shot money could be found to • cover Nichol’s Salary for 6 months.

  12. Trigger Summary – ZEUS Collaboration Meeting Plenary Session FL, Low Energy testrun 59937 STD High Lumi Loose NC DIS slots 37, 46 EmPzHi 30 GeV Normal Run Low Energy Run • 0: NC DIS RCAL • 1: NC DIS B/RCAL • 2: PHP • 3: CC • 4: EXO + misc • 5-8: B/F/Bac/R MU • 9: any MU • 10: random, calib, ‘passthrough’ • 13: Abort/Accept=75% • 11: AbortCond/Accept=55% • Dominant FCLR Cuts • BG Cut • E-Pz >30 GeV • FL/Low energy running: FCLR very effective • FCLR can provide rejection factor 4.5, in stead of current factor 2.25!

  13. HERA’s Legacy

  14. The End

  15. O.S.U. Physics Analysis 2000-2006 Structure Function and High Q2 Camille Ginsburg (Physics Coordinator) Contact Interactions Jason Gilmore (Thesis) Limits on Production of R-Parity Violating SUSY particles Nicole Brümmer Spin-Dependence of Charged Current Cross Sections Albert Lee(Thesis), Nicole Brümmer

  16. Deep Inelastic Scattering Neutral Current Charged Current

  17. High Q2 NC/CC DIS Cross Section • Electroweak unification scale ~104 GeV2 • At Q2>104 GeV2 NC=CC • Statistically limited at high x/high Q2 • Cross sections sensitive to sea/valence quark • densities and electroweak parameters

  18. Nichol Brummer, SUSY-2005 Durham

  19. Physics with Polarized Beams Standard Model Neutral Current left/right handed particles interact unequally with Z0 Charged Current left-handed particles only HERA Transverse Polarization builds up naturally at HERA (Sokolov-Ternov effect) at HERA =30min Paverage=40% (depol. effects) The Cross section depends on polarization. One Searches for e.g. WR and tests Standard model. With one years data should be able to set limit MW(R) < 400 GeV

  20. Future 2005-2007 ZEUS Operations will end in mid-2007 ZEUS has produced quality physics in the last fourteen years. HERA has doubled our data sets in the last 1.5 year. The Ohio State Group will continue to monitor and maintain the ZEUS Fast Clear With the new luminosity this group will continue to study high Q2 high x physics and new Electron Spin Physics

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