ZEUS Status DESY PRC, 30 October 2002 E. Tassi, NIKHEF Software/Detector status 2002 Running: 2002...

ZEUS StatusZEUS Status

DESY PRC, 30 October 2002DESY PRC, 30 October 2002E. Tassi, NIKHEFE. Tassi, NIKHEF

Software/Detector statusSoftware/Detector status 2002 Running:2002 Running:

Background studiesBackground studies Physics ResultsPhysics Results OutlookOutlook

E. Tassi - DESY PRC, 30 October 20022

ZEUS ComputingZEUS Computing

Computer farm:Computer farm:Recently upgraded with Recently upgraded with 40 Intel Xeon/2.2 GHz processors40 Intel Xeon/2.2 GHz processors - doubled system´s computing power- doubled system´s computing power

Mass Storage System:Mass Storage System:Moved from Moved from SSFSSF to to dCachedCache ( (DESY/FNAL)DESY/FNAL)

- cached access to the storage system- cached access to the storage system

and CPU upgrade have greatlyand CPU upgrade have greatly

improved turnaround of analysis jobsimproved turnaround of analysis jobs

16 Mio of events processed so far...16 Mio of events processed so far...


ZEUS Application SoftwareZEUS Application Software

ZeZeus us VisVisualizationualization PackagePackage

Since the first „slim release“Since the first „slim release“ rapidly becoming a maturerapidly becoming a mature productproduct

Among new featuresAmong new features Full event informationFull event information

Already an invaluable toolAlready an invaluable tool

Improved 2D/3D renderingImproved 2D/3D rendering New detectors includedNew detectors included -FTD/STT/RTD/MUON-FTD/STT/RTD/MUON Used as front-end of theUsed as front-end of the online event displayonline event display


ZEUS detector statusZEUS detector status

Zeus Micro Vertex DetectorZeus Micro Vertex Detector

Straw-Tube TrackerStraw-Tube Tracker

Photon Cal. and Lumi SpectrometerPhoton Cal. and Lumi Spectrometer

Detector operationalDetector operational - 2000 components re-commisioned- 2000 components re-commisioned - Since Feb. 22 could operate CTD- Since Feb. 22 could operate CTD (although at lower beam currents - Background)(although at lower beam currents - Background) Concentrate on new components:Concentrate on new components:


LUMI and STTLUMI and STT

LUMILUMI Photon Cal.Photon Cal. and and spectrometerspectrometer both both

taking data and measuring luminositytaking data and measuring luminosity Calibration/alignement/acceptance Calibration/alignement/acceptance studies on-going studies on-going

STTSTT Integrated in the data taking Integrated in the data taking STT s/w in the reconstruction suiteSTT s/w in the reconstruction suite After installation a few h/w problems After installation a few h/w problems were identified. Detailed plan to curewere identified. Detailed plan to cure them has been elaborated.them has been elaborated.


Micro Vertex Detector Micro Vertex Detector

SuccesfullySuccesfully taking data taking data MVD reconstruction codeMVD reconstruction code thoroughly exercised/tunedthoroughly exercised/tuned Global Tracking TriggerGlobal Tracking Trigger running and producingrunning and producing first resultsfirst results Preparation for the final Preparation for the final alignement well underwayalignement well underway


Background StudiesBackground Studies

Huge effort devoted by the collaboration (see ZN-02-018 and forthcoming addenda) Main concern: operating the CTD Background sources: positron-beam related: SR,e-gas proton-beam related: p-gas Our present understanding and possible remedies


Synchrotron radiation and e-gasSynchrotron radiation and e-gas Synchrotron RadiationSynchrotron Radiation Direct (marginal) and backscattered Direct (marginal) and backscattered photons entering CTD and producing photons entering CTD and producing ionizationionization Exploit detailed simulation suiteExploit detailed simulation suite Factor ~10 should be achievable by Factor ~10 should be achievable by implementing shielding measures andimplementing shielding measures and modification of beamline elementsmodification of beamline elements

Fairly good understanding of the problem..Fairly good understanding of the problem..

Design: C5a with integrated shieldDesign: C5a with integrated shield

e-gase-gas Origin of the problem...Origin of the problem... C5a reduced thickness:C5a reduced thickness: only factor 2 reductiononly factor 2 reduction Need improvement of the vacuum Need improvement of the vacuum

lower momentum e


proton-gasproton-gas Will become the main source of BG Will become the main source of BG when reducing SRwhen reducing SR MC simulation implementingMC simulation implementing p-gas (HERWIG minimum bias)p-gas (HERWIG minimum bias) - mainly sensitive to 20m from IP- mainly sensitive to 20m from IP - vacuum profile from MC/Data comp.- vacuum profile from MC/Data comp. Dynamic vacuumDynamic vacuum Marginal improvements fromMarginal improvements from modification of our beamlinemodification of our beamline

Need much improved vacuumNeed much improved vacuum (especially close to the IR)(especially close to the IR)


A Possible ScenarioA Possible Scenario

@ nominal Ie=58 mA @ nominal Ip=130 mA

tota

lto

tal

p-gas

e-gas

p-gas

e-gassynch synch

Ie=50ma

Ie~60mA Ip~130mA


Physics ResultsPhysics Results

Highlights:Highlights: QCD fits, High-Q2 NC and CC cross sectionsQCD fits, High-Q2 NC and CC cross sections DIS inclusive jet cross sections DIS inclusive jet cross sections Beauty productionBeauty production Deeply Virtual Compton ScatteringDeeply Virtual Compton Scattering Searches for isolated taus and missing PtSearches for isolated taus and missing Pt

HERA II Physics: see K. Long and P.SchleperHERA II Physics: see K. Long and P.Schleper last PRC´s presentationslast PRC´s presentations

ZEUS rich physics program:ZEUS rich physics program: 45 contributed papers to ICHEP 200245 contributed papers to ICHEP 2002


ZEUS-Oep,110 pb-1

ZEUS-S uv,dv

QCD Fit, High-QQCD Fit, High-Q22 NC and CC NC and CC

ZEUS NLO QCD FitZEUS NLO QCD Fit Now publishedNow published Zeus PDFs with uncertainties and Zeus PDFs with uncertainties and ss

Zeus-Only valence PDFsZeus-Only valence PDFs

High Q2 NC and CC analysesHigh Q2 NC and CC analyses e+p NC/CC approaching completione+p NC/CC approaching completion - will complete ZEUS HERA I inclus.cross sections measurements at high-Q- will complete ZEUS HERA I inclus.cross sections measurements at high-Q22

Important input for:Important input for: -Testing the EW sector of the SM-Testing the EW sector of the SM -Learn more about valence PDFs at high-x-Learn more about valence PDFs at high-x

ZEUS/H1 working group established and doing good progress...ZEUS/H1 working group established and doing good progress...

s(Mz) =0.1166 0.00080.00320.00360.0018 uncor. corr. norm. model


NC DIS inclusive jet cross sectionsNC DIS inclusive jet cross sections Direct sensitivity to s and the gluon density Reduced theoretical unc. w.r.t. dijet cross sections (infrared insensitive)

Analysis: Single and double differential cross measured for Q2 > 125 GeV2 and EB

T,jet > 8 GeV and compared to NLO QCD predictions.

As a result of a QCD fit: precise determination of s (MZ)

96/97 data set, incl. K in the Breit frame


NC DIS inclusive jet cross sectionsNC DIS inclusive jet cross sections

Agreement at high-Q2 and high-EAgreement at high-Q2 and high-ET,jetT,jet


Inclusive jet cross sectionsInclusive jet cross sections


Beauty ProductionBeauty Production

Rich testing ground of QCDRich testing ground of QCD - NLO pQCD:- NLO pQCD: FMNR (PHP), HVQDIS (DIS)FMNR (PHP), HVQDIS (DIS)

- DGLAP vs CCFM evolution- DGLAP vs CCFM evolution - Fragmentation- Fragmentation

ZEUS contributing with a setZEUS contributing with a setof precise measurementsof precise measurementsin the PHP and DIS regimes in the PHP and DIS regimes

Boson-Gluon Fusion (direct)

Gluon-Gluon Fusion (resolved photon)


Beauty productionBeauty production

b visible cross sections in PHPb visible cross sections in PHP

(ep(epbbXbbX e Jet Jet e Jet Jet X) X)

Q2 <1 GeVQ2 <1 GeV22, 0.2< y <0.8, 0.2< y <0.8At least two jets in the Lab frame with:At least two jets in the Lab frame with: PPT,jet1(jet2)T,jet1(jet2) > 7(6) GeV, > 7(6) GeV, jetjet < 2.5 < 2.5 At least on muon with:At least on muon with: ppT,T, > 2.5 GeV, -1.6 < > 2.5 GeV, -1.6 < <2.3 <2.3

New result:96/00 ~98 pb-1

3 times more statistics

Data/NLO ~1.4Data/NLO ~1.4Agreement within uncertaintiesAgreement within uncertainties


Beauty productionBeauty production

(ep(epbbXbbX e Jet e Jet X) X)

QQ22 < 2 GeV < 2 GeV22, 0.05< y <0.7, 0.05< y <0.7At least one jet in the Breit frame with:At least one jet in the Breit frame with: EET,jet1T,jet1 > 6 GeV, > 6 GeV, jetjet < 2.5 < 2.5 At least one muon with:At least one muon with: ppT,T, > 2.0 GeV, 30 > 2.0 GeV, 30ºº < < < 160 < 160ºº

First diff. B visible cross sections in DISFirst diff. B visible cross sections in DIS

New result: 99/00 ~ 60 pbNew result: 99/00 ~ 60 pb-1-1

Agreement with NLOAgreement with NLO


Deeply Virtual Compton Deeply Virtual Compton ScatteringScattering

Simple process:Simple process:

a diffractively produced a diffractively produced real photonreal photon

Great theoretical interest:Great theoretical interest: - Generalized Parton Distributions- Generalized Parton Distributions ....but also Color Dipole Models,....but also Color Dipole Models, VM productionVM production

(*p p) measured as afunction of Q2 and W in e+p and e-p


DVCSDVCS

No differences between e+ and e- samplesNo differences between e+ and e- samples Steep rise with W Steep rise with W hard underlying processhard underlying process


DVCSDVCS

Data precise enough to start discriminating differentData precise enough to start discriminating differenttheoretical models. See also hep-ph/0208160theoretical models. See also hep-ph/0208160


Search for isolated Search for isolated s s Prompted by high pt-lepton searchesPrompted by high pt-lepton searches (electron and muon channels)(electron and muon channels) H1 see excess, ZEUS compatibleH1 see excess, ZEUS compatible with the Standard Model with the Standard Model

Look at the Look at the channel... channel...

Search for hadronic decays (65% BR, predominantly in one charged hadron) Analysis based on a Multi-observable discrimination technique (use 6 jet-shape releted variables) Aim: separate -induced jets from quark- and gluon-initiated jets (-jets pencile like, low charged particle multiplicity and charge 1)


Search for isolated Search for isolated ss

ResultsResults

2 events observed (P2 events observed (PTT>25)>25)

0.12 0.12 0.02 expected from SM 0.02 expected from SM


Summary and OutlookSummary and Outlook

Zeus taking data and in good shapeZeus taking data and in good shape Huge effort devoted to background studiesHuge effort devoted to background studies ZEUS rich physics program well underway ZEUS rich physics program well underway Looking forward to the forthcoming dataLooking forward to the forthcoming data taking period...taking period...


spoolspoolsynch+e-gas

synche-gas

CTD ~ 7*Ie+1.26*Ie 1.3

CTD ~ 1.17*Ie+0.63*Ie 1.3

e-gas

synch

ZEUS Status DESY PRC, 30 October 2002 E. Tassi, NIKHEF Software/Detector status 2002 Running: 2002...

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