ZEUS Physics Overview A sampling of recent physics results –Charged current cross-section –Charm production in DIS –Exotic hadrons (glueballs and pentaquarks) –Contact interactions, extra-dimensions limits HERA implications for the LHC : an example case HERA-LHC workshop Current status and conclusion R. Yoshida Argonne National Laboratory ZEUS spokesman DOE visit, 11 March 2004 Please see also my HEPAP talk

Papers with 100+ citations (spires) Pace of paper production has not slacked off—if anything increased in the recent years. ZEUS papers are consistently among the most cited papers. A sampling of recent papers 

Argonne analysis

Exotic baryons at ZEUS Pentaquark candidate Glueball candidate Argonne analysis

Contact interactions, extra-dimensions limits

Implications of HERA for the LHC Parton distributions  relevant to all processed at LHC Diffraction  HERA measurements may make quantitative prediction. Important as background for many processes, and also as signal (diffractive Higgs) Underlying event, fragmentation  HERA ep environment allows for precise measurement of non-perturbative effects. Important to assess background. Hard cross-sections  precise jet cross-sections, heavy quark cross-sections. Important ingredient in sorting out new physics at the LHC Many other issues … One example 

Precise jet measurements are being made at ZEUS: 1% energy scale NLO QCD under good control Precise measurement of  s DIS jets An example: impact of ZEUS data on LHC physics

Photoproduction of jets Jets can probe the gluon Because measurement and theory are under control  gives meaningful information in QCD analysis of proton PDF

Very Preliminary xg Including the jet data (using quantitative uncertainties) in the QCD fit of parton densities : Inclusive DIS measurements: scaling violation gives access to gluon densities

Just as at the Tevatron, high Et jets at the LHC is one of the most important windows to new physics. Almost a decade ago, Tevatron high Et jets seemed to indicate some new physics. PDF uncertainties, unquantified Difficult systematics of jet measurement Note: ZEUS jet uncertainties are a few %

Extra-dimension study for ATLAS Medium to high-x gluon distributions, Jet uncertainties -- important in extending physics reach.

Organized by HERA/DESY and LHC/CERN, and sponsored by the labs. The main workshop for LHC in year long. Aim for quantitative studies.

To identify and prioritize those measurements to be made at HERA which have an impact on the physics reach of the LHC. To encourage and stimulate transfer of knowledge between the HERA and LHC communities and establish an ongoing interaction. To encourage and stimulate theory and phenomenological efforts related to the above goals. To examine and improve theoretical and experimental tools related to the above goals. To increase the quantitative understanding of the implication of HERA measurements on LHC physics. Goals of the workshop

 Luminosity progress Rate of lumi accumulation  1 fb-1 in 1000 days goal till summer04 Goal: ~.7-1 fb-1 in 1000 days HERA has began to deliver luminosities approaching the required rate

The ZEUS detector is working well. New MVD and STT   Neutral Current DIS Working well

Conclusions ZEUS is in the process of producing numerous important results from HERA I spanning topics ranging from pentaquarks to extra- dimensions. The importance of HERA results to LHC is recognized by physicists at LHC and at HERA  strong support from CERN and DESY on the HERA-LHC workshop. HERA is the only HEP collider in Europe until the LHC turn on. HERA is a source of young physicists with strong experiences in high-rate hadron-collider experimentation and QCD. HERA and ZEUS are about to enter its most productive stage. Five fold increase in luminosity, new detectors (MVD, STT) and lepton beam polarization. The next 3.5 years (end of HERA II mid-2007) is the culmination of an enormous efforts by all of the international members of the ZEUS collaboration.