1 / 51

New Results from D0

New Results from D0. The D0 collaboration The TeVatron Physics program with the upgraded detector Detector performances Some recent results. Run II. 18 countries 78 institutes 664 physicists. Run I (1990-1996): discovery of the top quark. Run II (2001-2009):.

nan
Télécharger la présentation

New Results from D0

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. New Results from D0 The D0 collaboration The TeVatron Physics program with the upgraded detector Detector performances Some recent results New Results from D0 - Humboldt University 27/06/ 2003

  2. Run II 18 countries 78 institutes 664 physicists New Results from D0 - Humboldt University 27/06/ 2003

  3. Run I (1990-1996): discovery of the top quark Run II (2001-2009): Accelerator upgrade: Detector upgarde: New inner detector with central magnetic field Old components: extended coverage and made faster New Results from D0 - Humboldt University 27/06/ 2003

  4. New Results from D0 - Humboldt University 27/06/ 2003

  5. The upgraded detector + FPD to detect diffractive events New Results from D0 - Humboldt University 27/06/ 2003

  6. TeVatron and detector performances New Results from D0 - Humboldt University 27/06/ 2003

  7. Spec: 5 kHz 1000 Hz 50 Hz Level3 Level 1 Level 2 tape Operating: 1.2 kHz 800 Hz 50 Hz Data are reconstructed in a couple of days Several Tbytes per week 400 M events on tape  220 Tbytes stored New Results from D0 - Humboldt University 27/06/ 2003

  8. Luminosity prospects In 2003 Until 2009 Plan currently under intense discussion New Results from D0 - Humboldt University 27/06/ 2003

  9. The Physics Program • The unfinished tests of the Standard Model • Higgs – does it exist? • CKM mixing matrix – Vtb, CP violation? • High energy EW Phenomena – Afb, 3gc • Towards the unification of the 4 forces in a finite theory • SUSY – minimal version ? • (Large) Extra Dimensions – limits? • Other new phenomena – a guide beyond the MS New Results from D0 - Humboldt University 27/06/ 2003

  10. LHC 2003 New Results from D0 - Humboldt University 27/06/ 2003

  11. Detector and software performances (Winter conferences 2003) « Yesterday’s discovery is today’s calibration … - Richard Feynman … and tomorrow’s background » - Val Telegdi New Results from D0 - Humboldt University 27/06/ 2003

  12. Trackers Reconstruction of rare particles Pic positions to calibrate B-field and energy loss in detector material New Results from D0 - Humboldt University 27/06/ 2003

  13. New Results from D0 - Humboldt University 27/06/ 2003

  14. First step toward studying CP violation in the B system New Results from D0 - Humboldt University 27/06/ 2003

  15. < >= 1.561 ± 0.023(stat)±0.074(syst) ps < >= 1.564 ± 0.014 ps (PDG) New Results from D0 - Humboldt University 27/06/ 2003

  16. Calorimeter performances 2300 Z->e+e- 40000 W->enu to calibrate the calorimeter Limit on high mass e+e- pairs: limits on Z’ but also on other exotics (see later) New Results from D0 - Humboldt University 27/06/ 2003

  17. Identification of EM objects Dominated by electrons Dominated byphotons (0) New Results from D0 - Humboldt University 27/06/ 2003

  18. New Results from D0 - Humboldt University 27/06/ 2003

  19. DØ ETmiss in jet events Missing Transverse Energy MET and jets 4 pb-1 Pt(j1)>100 GeV, Pt(j2)>20 GeV Residual MET (from QCD): ~exp(-MET/14[GeV]) MET = 180 GeV Mjj = 98 GeV New Results from D0 - Humboldt University 27/06/ 2003

  20. Performance of the muon detector J/  m+m- with and without tracker 5200 Z->mu mu collected New Results from D0 - Humboldt University 27/06/ 2003

  21. New:Taureconstruction MC Data Important for SUSY studies New Results from D0 - Humboldt University 27/06/ 2003

  22. b-tagging A « must » for Higgs and SUSY IP or SVX SLT New Results from D0 - Humboldt University 27/06/ 2003

  23. Some recent results (Winter conferences of 2003) • Tests of the Standard Model • QCD (see before) • W and Z production • rediscovering the top(xsec, mass) • Higgs searches • where do we stand? • New phenomena searches • SUSY • Lepto-Quarks • Large Extra Dimensions • Z’ (see before) New Results from D0 - Humboldt University 27/06/ 2003

  24. PDG combined Exp PDG SM Theoretical prediction Measure (ppW)(W  e)(Z) R= (ppZ)(W)(Z  ee) Extract W and Z production New Results from D0 - Humboldt University 27/06/ 2003

  25. Rediscovering the top-quark Cross section mesurement Mesurement of the mass New Results from D0 - Humboldt University 27/06/ 2003

  26. em mm ee Z→tt→ll WW→ll 0.02 ± 0.01 0.001± 0.001 0.02 ± 0.02 0.00 ± 0.00 0.02 ± 0.02 0.001 ± 0.001 Z→ll DY→ll QCD, W+jets -- -- 0.05 ± 0.01 0.20 ± 0.12 0.20 ± 0.21 0.18 ± 0.18 0.98 ± 0.48 All BG 0.07 ± 0.01 0.60 ± 0.30 0.60 ± 0.30 Expected Signal 0.50 ±0.01 0.3 ± 0.04 0.25 ± 0.02 Observed 1 2 4 Jan 22 2003 run: 169920 event: 8545882 e+- + 2 jets 33-48 pb-1 Mmm ET (GeV) New Results from D0 - Humboldt University 27/06/ 2003

  27. Main background: W+nj and QCD (nj) 40-49.5 pb-1 SLT: New Results from D0 - Humboldt University 27/06/ 2003

  28. lepton+jets only all channels combined New Results from D0 - Humboldt University 27/06/ 2003

  29. Reanalyse of the Run I data in l+jets channel • Exactly 4 jets – less combinatorial background • Proper use of the matrix elements Previousely published: 5,6 GeV – equivalent to 2,4x increase of statistics Systematic error: ~6 GeV dominated by error on JES New Results from D0 - Humboldt University 27/06/ 2003

  30. LEP excluded at 95% C.L. Towards finding the Higgs indirectly directly dmH/dmW ~ 50 GeV/25 MeV dmH/dmt ~ 50 GeV/4 GeV New Results from D0 - Humboldt University 27/06/ 2003

  31. High pT lepton tag: • either HW or HZ and H->bb: M<140 GeV • small cross section • background: W/Z+jets,QCD • b-tagging is a « must » • or H->WW(*): M>130 GeV • larger cross section (gg->H) • background: WW,W/Z+jets,tt,QCD New Results from D0 - Humboldt University 27/06/ 2003

  32. Combined W + Jets leading jet New Results from D0 - Humboldt University 27/06/ 2003

  33. Z + Jets New Results from D0 - Humboldt University 27/06/ 2003

  34. HWW(*) e+e-nn L=44.5 pb-1 Selection is optimized for mH = 120 GeV New Results from D0 - Humboldt University 27/06/ 2003

  35. (HWW emnn) x 50 Selection New Results from D0 - Humboldt University 27/06/ 2003

  36. Selection optimized for MH=160 GeV New Results from D0 - Humboldt University 27/06/ 2003

  37. The way still to go … New Results from D0 - Humboldt University 27/06/ 2003

  38. Searches for New Phenomena • SUSY • Di- and Tri-leptons • Gauge Mediated Symmetry Breaking • Lepto-Quarks • Large Extra Dimensions • Z’ (see before) New Results from D0 - Humboldt University 27/06/ 2003

  39. SUSY is a broken symmetry: SUSY partners are massive many more parameters to describe breaking mSUGRA model contains 5 parameters R-parity is approximately conserved: severe limits on B- and L-violating processes SUSY partners are pair produced LSP exists, neutral and weakly interacting Basic signature is MET and multiple jets and leptons from cascade decays main bg is tt and gauge boson pair production Small violation of R-parity is not excluded: allows single resonant production of SUSY p’s many more jets/leptons in final state additional couplings (48) New Results from D0 - Humboldt University 27/06/ 2003

  40. The « golden » signature: tri-leptons + MET from chargino-neutralino pair production MET from neutral WI LSP e+ e + lepton Cut Background Data pT e1 > 15 GeV 3216 +/- 43 3132 pT e2 > 10 GeV 10 < m(ee) < 70 GeV 660 +/- 19 721 MT >15 GeV 96+/-8 123 Isolated track pT > 5 GeV 3.2+/-2.3 3 Missing ET > 15 GeV 0 +/- 2 0 e + m + lepton 1.5 +/- 1.5 2 • Results for ee + lepton • ~3-6 % efficiency for 2 pts en mSUGRA • s x BR = 3.5-2.2 pb excluded New Results from D0 - Humboldt University 27/06/ 2003

  41. At least 1 e w/ pT> 15GeV and at least 1 mu w/ pT> 15 GeV and MET Agreement between data and the SM -> limits on  x Acc(400->100 fb) New Results from D0 - Humboldt University 27/06/ 2003

  42. GMSB: LSP is the gravitino NLSP is the lightest neutralino Limit close to Run I New Results from D0 - Humboldt University 27/06/ 2003

  43. Searches forLeptoQuarks LQ’s appear in extended gauge sectors • Production • qg  LQ + LQbar • gg  LQ + LQbar • qqbar  LQ + LQbar • Decay • LQLQ  l+l-qq, • LQLQ  l±nqq, • LQLQ nnqq • Experimental signature • 2 high pt isolated leptons + jets • one isolated lepton + MET + jets • MET + jets New Results from D0 - Humboldt University 27/06/ 2003

  44. Search for 2nd generation Lepto-Quarks 2 opposite sign muons with pT > 15 GeV, 2 jets with pT > 20 GeV, M > 110 GeV MLQ2 > 157 GeV (~30 pb-1) (Run I: 200 GeV) New Results from D0 - Humboldt University 27/06/ 2003

  45. Search for Large Extra Dimensions ED’s are important ingredients for unifying gravity with other interactions (K-K). In string theories, ED’s restore QM probabilities in the range [0,1]. ED’s are compact (since not yet seen). New Results from D0 - Humboldt University 27/06/ 2003

  46. New Results from D0 - Humboldt University 27/06/ 2003

  47. Search for Large Extra Dimensions Mmm= 460 GeV New Results from D0 - Humboldt University 27/06/ 2003

  48. Conclusions • The Tevatron has delivered significantly more luminosity than in Run I and at least 20 x more is expected in the coming years • The upgraded detector is entirely commissioned and its performances are superior to the previous one • Several results are close to or even better than those obtained in Run I • D0 is looking forward to many new results already for this years summer conferences continuing until the startup of the LHC New Results from D0 - Humboldt University 27/06/ 2003

  49. New Results from D0 - Humboldt University 27/06/ 2003

  50. New Results from D0 - Humboldt University 27/06/ 2003

More Related