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Task A: ZEUS 2005-2006. N. Brummer, L.S. Durkin, A. Lee, 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 2005-2006 N. Brummer, L.S. Durkin, A. Lee, 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 Correction Masks Designed and Built FastClear Trigger Processor Fast (15sec) Cluster Finder Electron Identification Kinematic Variables E-PZ Beam Gas Rejection Manufactured Optics for Barrel Calorimeter Presampler
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 !
Personnel 2005-2006 OSU ZEUS Effort is Bare Bones - Nicole Brummer (100%) at DESY Trigger Coordinator(2002-2004) - Grad Student Albert Lee at DESY
Background Problems fixed ! • Synchrotron radiation fixed • e-gas decreased • p-gas decreased HERA I (8 years) 193 pb-1 HERA II (1.5 years) 203 pb-1 • New Data has Polarized Electron/Positrons • 4X increase in e-p Data
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
O.S.U. Physics Analysis 2000-2005 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
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 / (2Pq) Bjorken-x momentum fraction of struck parton y = (Pq)/(Pk) Inelasticity relative energy transfer to the proton
Deep Inelastic Scattering Neutral Current Charged Current
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
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
Charge Current Cross Section This analysis will be Albert Lee’s Ph D Thesis
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