Task A: ZEUS 1999-2000

N. Brummer, B. Bylsma, L.S. Durkin, J. Gilmore, C. Ginsburg,

C.L. Kim, 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 Tiles5000 Wavelength-Shifter Light Guides and Correction Masks

Designed and Built FastClearTrigger Processor

Fast (15sec) Cluster Finder Electron Identification Kinematic Variables E-PZ

Beam Gas Rejection

Manufactured Optics forBarrel Calorimeter Presampler

Group History on ZEUS (cont.)

Monte Carlo Production

Sole U.S. University to provide Computer Time

Farm updated in 1998 to 15 Linux PC’s increasing output by 6X

Administrative U.S. ZEUS Spokesman3 Physics Coordinators Run 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 Assist. Prof. Assist. Prof.Korea U. Kyungpook U. U. of Florida

3 faculty Positions out of 5 postdocs !

HERA Luminosity

- First Interaction 1992- Beam Vaccum graded 1997- P Energy 820-900 GeV 1997

1993 e- 1.09 0.58 0.541994 e- 1.08 0.41 0.28

e- 93-94 2.17 0.99 0.82

1994 e+ 5.11 3.3 3.021995 e+ 12.31 7.27 6.621996 e+ 17.16 11.27 10.711997 e+ 36.35 29.09 27.691999 e+ 28.54 21.58 19.682000 e+ 49.07 38.22 35.17

e+ 94-00 148.54 110.73 102.89

1998 e- 8.08 5.16 4.691999 e- 17.12 11.86 11.38

e- 98-99 25.2 17.02 16.07

Year

ZEUS lumi (pb-1)

HERA delivered

ZEUS on-tape

ZEUS analysis

O.S.U. Physics Analysis 1999-2000

Structure Function and High Q2

Camille Ginsburg, Physics Coordinator Contact Interactions

Jason Gilmore, Thesis

Inclusive D* Photoproduction Cross Section

C.L. Kim, Main Analysis

Total Photoproduction Cross Section

Camille Ginsburg, Main Analysis

2W

2

2W

W MQ

MP

N.C. Dependence on 2Z

2

2

Z MQ

QP

- clear evidence for Z exchange in spacelike DIS

Death of a Leptoquark

Photoproduction

HERA basically is 2 colliders in one !

For low Q2 a nearly real photon exchange

P Collider

E 10-15 GeVW 80-120 GeV

Weizacker-Williams corrects to ‘real’ photon

Summary

- NLO calculation below data particularly in forward direction

- Fragmentation agrees with other experiments

D* Fragmentation Function

Subject Collaboration(s) CitationsTop Quark CDF/D0 393+389/690E/W Parameters LEP 251F2 Measurement ZEUS/H1 231/249Z Width Delphi/Aleph/Opal/L3 241/237/222/210Large Rapidity Gap ZEUS/H1 227/267W Boson Mass CDF 191

tot(p) ZEUS/H1 150/122Jet Production CDF 133High x,Q2 ZEUS/H1 121/119Jet Production OPAL 114

Top Ten Collider Physics Journal Citations (1998)

HERA has NOT Met Lumiosity Expectations

Quotes Circa 1987

“ 100 pb-1 /ZEUS YEAR” “ the MC Contains 1000 pb -1 worth of data”

HERA Luminosity Upgrade 7X Increase

10 Months Shutdown Starting Sept 2000 - improve beampipe vaccuum - install short focusing quad near interaction region

ZEUS Detector Upgrades

- Silicon Vertex Chamber- Straw Tube Tracking Chambers

Fast Clear will be Important

With 7X Luminosity New Physics Analyses will be Possible !

With 1000 pb-1 this will be a Precsion Measurement !

Extraction of xF3

xF3 parity violating term from Z0 exchange

Physics with Polarized Beams

Future

ZEUS has produced quality physics in the last eight years

HERA is undergoing a major luminosity upgrade beginning in September

The Ohio State Group will continue to analyse new data during the shutdown

With the new luminosity this group will continue to study high Q2 high x physics