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ZEUS Status.Pdf ZZEEUUSS statustatuss reprepoortrt -- recenrecentt resuresultslts SS..CChekanovhekanov ((AANNL) for the ZEUS Colllaboratiion DESY PRC review (October 28, 2004) • Data taking and running conditions • Detector status • Physics Highlights • Summary CC DIS at Q2~ 3000 GeV2 DDaatata tatakkiningg:: 22000033--22000044 Total gated: ~45 pb-1 Gated/HERA delilivered ~ 54% Nearlly alll taken data can be used for physicics All detectors are functional Gated/MVD > 95% Gated/STT > 95% S.Chekanov, DESY PRC review (Oct 2004) 2 ZEUZEUSS ddaatata tatakkiningg eefficfficieiennccy-y-II Signiifiicant iimprovements during Jully-August Effiiciency went up since May due: better beam conditions (better vacuum, less spikes) improvements in DAQ/trigger Remaiiniing iineffiiciency: ~10% - HERA initial luminosiity tuning present ~5-8% - HV trips in central tracking (CTD) ~5-8% - DAQ problems Room for further iimprovements: speed up run starts reduce DAQ problems Efficiency (2000) reduce sensitiviity to CTD HV trips Last ZEUS real efficiency 80-90% PRC S.Chekanov, DESY PRC review (Oct 2004) 3 ZEUZEUSS ddaatata tatakkiningg eefficfficieiennccy-y-IIII Typiicall trigger dead tiime was 5-10% iin May (at llast PRC): removiing very busy events due to beam gas colllliisions from the trigger chaiin biiggest iimprovement - regenerated pumps iin June ✔ vacuum was improved at least by a factor two Current trigger dead time ~ 1-2% up to Ie~50 mA & Ip~100 mA Commissioniing of Glloball Tracking Trigger (GTT) at second-levell trigger fiiniished: iincludes iinformatiion from CTD, STT & MVD: ✔ better beam gas rejection and physics filters ✔ extend to forward region ✔ improve vertex resolution ✔ potentially can reduce trigger rates by ~15-30% some physics fiillters allready use the GTT ✔ allows heavy-flavor tagging on-line in the SLT fullll operatiion for e- runniing S.Chekanov, DESY PRC review (Oct 2004) 4 22000033/2/2000044 ddaatata tatakkiningg New components: Silliicon Miicro-Vertex-Detector (MVD) New forward tracking wiith STT New tracking trigger Beauty candidate: 2 jets + 2 muons J/Psi candidate New data are already an important part of ongoing physics program (see ICHEP04) → will be discussed in context of particular physics topic S.Chekanov, DESY PRC review (Oct 2004) 5 StaStatutuss ooff MMVDVD && LLuummininoossityity mmoonnitoitorrss 47 M events collllected wiith MVD No big radiiatiion dose during May-August Detector iis iin good shape Relliiable detector operatiion → see physics resullts llater Lumi spectrometer Shielding upgrade + new set of radiiatiion moniitors Lumi callorimeter Good agreement witith Lumi spectrometer 2 NC DIS(Q >200) / Lumi (nb-1) S.Chekanov, DESY PRC review (Oct 2004) 6 TaTakkiningg ddaatata wwithith STTSTT ● STT buiillt to iimprove relliiabiilliity and effiiciency of tracking iin forward diirectiion ● STT/FRTD runniing at nominall HV during 2004 > 95% effiiciency ● Angullar coverage matches wellll wiith MVD and starts (θ < 23º) where CTD has llow acceptance ● MVD/STT matchiing iis iin progress ✔ With event vertex one can reach about 10% accuracy for 1-5 GeV ● STT was iincorporated iinto GTT & TLT (software and hardware are ready) Good STT-CTD-MVD matching: 90-95% efficiency for isolated tracks S.Chekanov, DESY PRC review (Oct 2004) 7 RReessuultslts ooff HHERERAA sshhuutdtdoowwnn ((AuAugg--SeSepp)) Generall and preventivive mainintenance and detector repaiirs Calorimimeter: smallllest number of UCAL bad channells for the llast 6 years Lumi detectors: Spectrometer: addititiional shiielldining agaiinst synchrotron radiiatiion Callorimeimeter: some ellectronics has been repaireired Feedbox/Sollenoiid: moniitoring was iimproved DAQ and trigger iimprovements ZEUS is ready for data taking S.Chekanov, DESY PRC review (Oct 2004) 8 MMaaggnneett hheeaatintingg bbyy STTSTT It was found that: STT ellectroniics has iinsuffiiciient coolliing Operatiion of STT ellectroniics can llead to temporary leaks iin sollenoiid iinsullatiion vacuum A serious sollenoiid faiillure cannot be repaiired in a short tiime STT stays off for now Investiigatiions are on-goiing S.Chekanov, DESY PRC review (Oct 2004) 9 ZEUZEUSS GGrridid HERA-II data rates create strong iincrease of MC productiion demand ATLAS Need access to grid resources ZEUS At the same tiime, keep the “tradiitiionall” productiion sites (funnel) 0.6 M events allready produced - samplles pass standard DQM & are iin use for physics anallysis ● Transparent iintegratiion of tradiitiionall Jobs per VO (snapshot at RAL) productiion system & grid The ZEUS Gateway Concept KEK ZEUS Integrated Rutherford Production System s ZEUS te si Montreal l Grid e n RAL n Tel Aviv Gateway Fu Bonn Scotgrid ... DESY ... S.Chekanov, DESY PRC review (Oct 2004) 10 PhyPhysisicscs outoutputput ZEUS SLAC SPIRES-HEP database s 40 me CDF i t 35 CLEO 0 30 ZEUS 0 OPAL 1 45 papers submitted to ICHEP04 25 ALEPH > H1 d 20 27 papers – new results e L3 t 15 BaBar ci D0 9 papers finished in 2004 s 10 n DELPHI o i 5 SLD t HERMES ca 0 i l b u collaboration p ZEUS papers are among most cited in literature S.Chekanov, DESY PRC review (Oct 2004) 11 ZZEUEUSS phyphysisicscs programprogram Proton structure, PDF Eleclectroweak unificicationion Jet productionion - QCD s determinatinationion photon struucturere Dififfractionion Heavy fllavor physicics (charm & beauty) Search for new physicics Particiclele productionion pentaquarks Q2 = -q2: 4-momentum transfer squared x: fraction of proton momentum carried by quark S.Chekanov, DESY PRC review (Oct 2004) 12 NNLOLO QQCCDD analanalyysisiss andand PDPDFF BGF process Inclusive DIS jets Dijets in PHP HERA data at high x are still less precise than fixed-target experiments Fixed-target experiments suffer from systematic uncertainties and rigorous treatment of uncertainties is difficult Include jet observables measured at ZEUS - sensitive to gluon at x~0.01-0.1 through BGF process S.Ch ekanov, DESY PRC review (Oct 2004) 13 ZEUZEUSS jjeetsts QQCCDD aannaalyslysisis ZEUS only fit ZEUS + JETS fits Improvement in determination of gluon densities at mid-to-high x Rigorous treatment of uncertainties S.Chekanov, DESY PRC review (Oct 2004) 14 DDISIS aatt HHERERAII:AII: ccoollisllisioionnss wwithith ppoolalarrizizeedd lelepptotonnss NC DIS: CC DIS: Z0 couples differently to the left and right Linear dependence on polarization handed lepton Contribution to all Q2 Contribution at high Q2 ± (P) = (1± P) ± (0) (dependence of electroweak terms in the CC CC cross section) HERA II data: 16.4 pb-1 with P= -40.2% -1 14.1 pb with P= 31.8% S.Chekanov, DESY PRC review (Oct 2004) 15 RReessuullttss oonn ppoollaarrizizaatiotionn.. HHEERRAAIIII ddaatata NC DIS CC DIS Polarization effect established in CC DIS More data are needed for NC DIS Agreement with the SM for both CC & NC DIS S.Chekanov, DESY PRC review (Oct 2004) 16 ααs(M(MZ)) detdetermermiinatnatiionon Most precise measurement from inclusive jets Most recent measurement Competitive results from 3/2 jet ratio Theoretical uncertainties dominate Influence on world average S.Chekanov, DESY PRC review (Oct 2004) 17 RRunningunning ααs • Covers significant range in energy scale • Running of αs in single experiment • Theoretical uncertainties dominate - NNLO QCD is needed S.Chekanov, DESY PRC review (Oct 2004) 18 CChhaarrmm pprroodduucctiotionn Charm production directly sensitive to gluon density in proton Look at “golden” decay channel: D* ® D0 ® K Low Q2 with BPC Increase of statistics for heavy-flavor analyses relies on : - extending the track acceptance to lower angles (MVD/STT) Agreement with NLO QCD for 2 four decades in Q - tagging with MVD S.Chekanov, DESY PRC review (Oct 2004) 19 CChhaarrmm sstutuddieiess uussiningg HHERERAA IIII ddaatata Charm tagging using decay length Use MVD detector Decay length significance Sl=l/σl First look at HERA II data shows that lifetime tagging with MVD works as expected Large potential for the future S.Chekanov, DESY PRC review (Oct 2004) 20 BeautBeautyy productproductiionon Driviven by gluons QCD calculationsions: – γp: FMNR (Frixiione et all.) – DIS: HVQDIS (Harriis, Smith) Mulltii-scalle problem - mb ~ 5 GeV hard scale ensures reliable QCD calculations - Q2 (DIS) b - PT (PHP, DIS) Data somewhat above massive NLO QCD S.Chekanov, DESY PRC review (Oct 2004) 21 BeBeaauutyty sstutuddieiess uussiningg HHERERAA IIII ddaatata rel • large mass leads to large pt of μ relative to jet axis • large B-lifetime: use μ impact parameter δ from MVD rel A beauty fraction 16.1 ± 2.7% extracted using pt method Gives consistent result with the impact-parameter method Large potential for the future S.Chekanov, DESY PRC review (Oct 2004) 22 InclusivInclusivee diffractiondiffraction wwithith LPLPSS andand charmcharm datadata Proton-taggiing method wiith LPS – xL> 0.9 – xIP < 0.06 – high Mx accessiblle (up to 40 GeV!) NLO QCD fiits iinclude LPS & charm data • Good description by the NLO QCD fit • Fraction of t-channel momentum carried by gluons ~82% at initial scale (Q2=2 GeV2) S.Chekanov, DESY PRC review (Oct 2004) 23 DDiffractiviffractivee dijetdijet photoproductionphotoproduction R=1 R=0.34 QCD factorizatiion: centrall probllem of hard diiffractiion Does not holld iin pp CDF measurement iis by factor 10 llower than NLO based on H1 diiffractiive PDF need a suppression factor resollved contributiion iin diiffractiive photoproductiion may reQuiire a simillar correctiion (factorizatiion breaking?) LRG 3<η<5 ( FPC region) Comparisons with M.Klasen & G.Kramer • 30-fold increase in luminosity compared
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