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Stato di ZEUS

Commissione Scientifica Nazionale 1 19-23 Settembre 2005 , Napoli. Stato di ZEUS. Enrico Tassi Universita’ della Calabria e INFN-Cs. Outline. HERA 2005 Running Prospettive future (2006/2007) ZEUS Data-taking (2005) Performance del rivelatore Contributo gruppi italiani

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Stato di ZEUS

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  1. Commissione Scientifica Nazionale 1 19-23 Settembre 2005 , Napoli Stato di ZEUS Enrico Tassi Universita’ della Calabria e INFN-Cs

  2. Outline • HERA • 2005 Running • Prospettive future (2006/2007) • ZEUS • Data-taking (2005) • Performance del rivelatore • Contributo gruppi italiani • Risultati di Fisica E. Tassi: Status of ZEUS

  3. HERA: Luminosita` • e- running! • N.B.16 pb-1 e-p (HERAI)/160 pb-1 e+p(HERAI-II) • Buone le prestazioni delle macchina nel 2005: • Ip~90-100 mA , Ie~30mA • Lspec~2 x 1030cm-2 s-1 mA-2 • Lpeak~5 x 1031 cm-2 s-1 • Lint = 150 pb-1 • Fine presa dati: 14 Nov/2005  LHERAII(2005) ~ 180-200 pb-1 > LHERAI • Ulteriori margini di miglioramento… E. Tassi: Status of ZEUS

  4. HERA operational statistics • Hardware faults ancora frequenti • Interventi durante lo shutdown invernale tesi a migliorare la situazione E. Tassi: Status of ZEUS

  5. HERA: Polarizzazione • P~20-30% → 30-40% • Flip regolare degli spin-rotators • ΔPsyst ~ 2% (obiettivo ~1%) E. Tassi: Status of ZEUS

  6. HERA: Running 2006/2007 F. Willeke (primavera 2004) • Lint(HERAII) ≥ 700 pb-1 • Runs dedicati negli ultimi mesi di data-taking?: • Low Ep running → FL • Increased Ep (1TeV) running → Ricerca di Lepto-quarks E. Tassi: Status of ZEUS

  7. ZEUS Data-Taking [nb-1] • Serie di “daily gated luminosity records” (1.2 pb-1) • ZEUS data-taking efficiency • in generale ≥ 80% • Microvertice (MVD) on 95% del tempo • Straw Tube Tracker (STT) spento (cooling insufficiente) • ~110 pb-1 di nuovi dati e–p on tape! E. Tassi: Status of ZEUS

  8. CAL bad channels vs ‘time’ Stato del rivelatore • Calorimetro: stabile • CTD: trip rate ok (nessun segno di ‘ageing’) • LUMI (Cal/Spettrometro) ok • MUON chambers ok • Le componenti centrali portano bene i loro anni! E. Tassi: Status of ZEUS

  9. Stato del rivelatore:Microvertice • MVD: • Segnale/Rumore ok • Dose assorbita ok • Commissioning • Huge amount of work • Efficiency estimates from NC DIS: (Tracks in CTD and MVD fiducial) • > 4 MVD hits > 2 MVD hits • Data 91.4% 99.3% • MC 93.8% 99.3% CC NC E. Tassi: Status of ZEUS

  10. Stato del rivelatore: STT • STT: attualmente spento perche’ la componente, per un cooling rivelatosi insufficiente, interferisce con il solenoide • Studio termico: Isolamento e cooling supplementari E. Tassi: Status of ZEUS

  11. add insulation & cooling Stato del Rivelatore:STT FDET/STT GO magnet • “Repair tool” pronto • Attivita’ principale durante lo shutdown invernale E. Tassi: Status of ZEUS

  12. Gap HERA-II: Produzione MC • Uno studio del 2003 ha rivelato l’inadeguatezza di “funnel” per le esigenze di produzione di eventi MC ad HERAII • Motivi: • Luminosita’ HERA-II • Nuovi rivelatori • Soluzione: Computing Grid Technology E. Tassi: Status of ZEUS

  13. ZEUS Offline:Grid-Based MC Production • Piu’ di 200 milioni di eventi prodotti • Il maggior contributo (~40%) dai 15 siti grid INFN! • >60% della produzione ZEUS MC ora su grid E. Tassi: Status of ZEUS

  14. Elisabetta Gallo (Fi) – ZEUS spokeperson • Massimo Corradi (Bo) – Physics Chairman Responsabilita’ gruppi italiani nel 2006 • Physics Groups’ coordinators: • Marta Ruspa (To) – Diffrattivo/Low-x • Enrico Tassi (Cs) – Funzioni di Struttura and Fisica Esotica dal 1 gennaio 2006 • Alessandro Polini(Bo) – Trigger Coordinator • Roberto Carlin(Pd) – MVD tech. Coordinator • + 1 Run coordinator ecc… E. Tassi: Status of ZEUS

  15. Risultati di Fisica 2005 • 10 articoli su rivista (→ 08/2005) • 42 “Contributed papers” per LP/EPS05 • 3 con dati con HERA II + MVD • Contributo italiano alle analisi di Fisica: • O(20) analisi • 14 talks a conferenze internazionali • Physics Highlights: • Dati nuovi - MVD - Contributo italiano E. Tassi: Status of ZEUS

  16. Physics Highlights:Pol. CC Inclusive Cross sections • Measured σ(tot)L,R± • Test of the EW sector of the Standard Model • Stringent limits on Exotics Physics (e.g. WR) with more data • NB uses 2004 e 2005 data! E. Tassi: Status of ZEUS

  17. Physics Highlights:Pol. NC Inclusive Cross sections • Agreement Data-MC • Effect of Polarization already visibile e-Rp e+Rp e-Lp e+Lp E. Tassi: Status of ZEUS

  18. Physics Highlights:NLO QCD Fits Gluon distribution: relative uncertainty in bins of Q2 • Parton distribution functions have been obtained by a rigorous fit to combined inclusive DIS & jet data • uncertainty of the mid-to-high x gluon distribution in inclusive DIS is very effectively constrained by the jet cross sections • sufficient sensitivity to determine PDFs entirely in one experiment • Impact on LHC-Physics (HERA-LHC workshop) E. Tassi: Status of ZEUS

  19. s Determination From NLO QCD Fits • This method can also be used to determine s(MZ) as a free parameter in the fit s(MZ) = 0.1183 0.0028 (exp.)  0.0008 (model)  0.0050 (th.) • in agreement with world averages(MZ)=0.1182  0.0027 • first precise determination of s from HERA data alone world average (Bethke 2004): E. Tassi: Status of ZEUS

  20. Strong Coupling Constant • Comprehensive average of s(MZ) measurements at HERA • conservative assumptions on correlations of theoretical uncertainties (higher order, PDFs, hadronisation) • s(MZ)=0.11860.0011 (exp)0.0050 (th) • experimental uncertainty ~1%, theoretical ~4% • Need for NNLO QCD E. Tassi: Status of ZEUS

  21. Altri dati nuovi e±p: D* D*+ D0+  (K-+)+ • About equal sample sizes of e+ and e- HERA-II data • HERA-I result stat. fluctuation e+p 40 pb-1 e-p 33 pb-1 m(D0+) - m(D0) E. Tassi: Status of ZEUS

  22. Beauty with MVD • Measurement with HERAII data (e+p) exploiting the MVD/Muon chambers • A combination of two variables is used to extract the b and c content: Ptrel Impact parameter δ: E. Tassi: Status of ZEUS

  23. Beauty with MVD • Combined 2D fit to ptrel and δ resulted in: fc=(52±10)% fb=(16.7±2.6)% • Fits to ptrel orδ alone are compatible but less precise  measure diff. cross section E. Tassi: Status of ZEUS

  24. Beauty with MVD • Phase-space: • Agreement with NLO QCD • Very promising E. Tassi: Status of ZEUS

  25. LeptonFlavour Violation • Hera is an ideal place to look for LQ-mediated interactions like: eq→μq’ , eq→τq’ • Special techinque developed to select final-state τs • In many cases the most stringent limits to-date E. Tassi: Status of ZEUS

  26. Exclusive Electroproduction of Vector Mesons • Very clean final state, large kinematical range • At HERA, observe transition from soft to hard regime • Example: J/ measurement • Differential cross sections show high sensitivity to the gluon density functions • challenge to understand diffractive scattering quantitatively E. Tassi: Status of ZEUS

  27. j/psi Electroproduction: W Dependence J/ • Highly sensitive not only to different models, but also to different gluon densities within the same model E. Tassi: Status of ZEUS

  28. Conclusioni • Buone le prestazioni di HERA nel 2005 • 110 pb-1 di dati e-p gia’ collezionati da ZEUS quest’anno • L’esperimento cosi’ come il rivelatore gode di ottima salute • Contributo italiano determinante nel management dell’esperimento, per il mantenimento del rivelatore e nelle analisi di Fisica • Il programma di Fisica ad HERA resta di grande interesse • La presa dati riprendera’ la seconda settimana di Febbraio e continuera’ ininterrottamente fino a Giugno 2007. E. Tassi: Status of ZEUS

  29. The End E. Tassi: Status of ZEUS

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