1 / 27

Tevatron Searches at Aspen 2005: Detectors, Dileptons, Di-photons, and More

In February 2005, Stefan Grünendahl presented Tevatron Searches at the Aspen Winter Conference. The presentation covered Tevatron status, luminosity projection, DØ and CDF detector updates, and searches in different channels such as dileptons, photons, leptons with missing transverse energy, jets with missing transverse energy, and other channels. Various mass limits, including those for Dileptons and di-photons, were discussed along with results related to W', RS Graviton, Large Extra Dimensions, compositeness, Higgs production, leptons with jets, and more. The talk also included details on recent findings regarding diEM and limitations on MS in the context of Large Extra Dimensions.

neva
Télécharger la présentation

Tevatron Searches at Aspen 2005: Detectors, Dileptons, Di-photons, and More

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. Tevatron Searches (non-SUSY) Aspen Winter Conference February 2005 Stefan Grünendahl For the DØ+CDF collaborations Outline: • Tevatron status and luminosity projection • DØ+CDF detector status + plans • Recently updated searches by channel • Dileptons • Photons • Leptons + missing ET • Jets + missing ET • Other channels Stefan Grünendahl Tevatron Searches @ Aspen 2005

  2. Tevatron Luminosity Outlook Tevatron Run I: 130 pb-1 @s=1.8 TeV Run II: @s=1.96 TeV; 0.5 fb -1recorded until 2005-1-10 Current maximum instantaneous luminosity ~100x1030cm-2s-1 • pp collider Z’ reach • 1983: 91 GeV (Z discovery) • 1985: 180 GeV • 1989: 218 GeV (SppS 7.4 pb-1 @s=630 GeV) • 1996: 690 GeV (TEV Run I 110 pb-1 @s=1.8 TeV) • 2004: 815 GeV (TEV Run II 200 pb -1 @s=1.96 TeV) Stefan Grünendahl Tevatron Searches @ Aspen 2005

  3. The Detectors • Both are 4 detectors with central solenoid and silicon vertex tracker • Differences in calorimetry, outer tracker, muon systems • More upgrades for 2005: • CDF: preshower (is installed), EM timing, various trigger improvements • DØ: Layer 0 Silicon, Tracker readout, various trigger improvements calorimeter solenoid tracker DØ Endcap/endplug CDF Stefan Grünendahl Tevatron Searches @ Aspen 2005

  4. cross reference: search vs. signature Signature marked in blue: updated since 6/2004 Stefan Grünendahl Tevatron Searches @ Aspen 2005

  5. spin 0 spin 1 spin 2 Dileptons Stefan Grünendahl Tevatron Searches @ Aspen 2005

  6. dileptons: mass limits DØ: 780(ee,200 pb-1) 680(mm,250 pb-1 ) DØ: 367/355 (mr-mp</>mW, ee only) 650 (ee,200 pb-1 ) 640 (ee,200 pb-1 ) 680 (ee,200 pb-1 ) 575 (ee,200 pb-1 ) 100 DØ: 340/250 (mr-mp</>mW ee only) http://www-cdf.fnal.gov/physics/exotic/r2a/20040916.dilepton_zprime/note_7286.pdf http://www-d0.fnal.gov/Run2Physics/WWW/results/prelim/NP/N22/N22.pdf DØ ee rT,wT http://www-d0.fnal.gov/Run2Physics/WWW/results/prelim/NP/N03/N03.pdf DØ ee Z’ http://www-d0.fnal.gov/Run2Physics/WWW/results/prelim/NP/N20/N20.pdf DØmm Z’ Stefan Grünendahl Tevatron Searches @ Aspen 2005

  7. W’ • CDF, Wen, based on 205 pb-1 • transverse mass fit, signal = right-handed W’ (V+A) • spectrum well described by SM • main syst. uncertainty at very high mass: electron E-scale Stefan Grünendahl Tevatron Searches @ Aspen 2005

  8. Di-photons • Search high-mass gg events for new physics • Backgrounds from • Standard model diphoton • Misidentifications: gj or jj where jet gives a hard π0 • Highest mass event: m(gg) = 405 GeV/c2 Stefan Grünendahl Tevatron Searches @ Aspen 2005

  9. RS Graviton Diphoton LED limit limit on G(1), the first graviton excitation in the Randall-Sundrum ‘warped’ ED model Combined CDF RS graviton result Stefan Grünendahl Tevatron Searches @ Aspen 2005

  10. ee and gg combined • D0 diEM search: best limit on RS-Graviton extension of Z’ analysis to set limit on G(1), the first graviton excitation in the Randall-Sundrum ‘warped’ ED model Highest-mass diEM candidate with invariant mass of 475 GeV and cosθ. of 0.01 (Run 177851, Event 28783974) Stefan Grünendahl Tevatron Searches @ Aspen 2005

  11. Large Extra Dimensions DØ: extract limit from 2d-fitmass vs cos (*) 95 %CL lower limits on MS [TeV]: mm diEM Currently best limits for n>2 Stefan Grünendahl Tevatron Searches @ Aspen 2005

  12. Compositeness • DØ dielectron analysis based on 270 pb-1 • Limits on compositeness scale for various models • LC > 3.6 – 9.1 TeV 3 TeV LL Four-fermion contact interaction interferes with SM D/Y production Black line: Run I limit Stefan Grünendahl Tevatron Searches @ Aspen 2005

  13. Dileptons: tt t(had) signature is a bit more complex than e or m; get track multiplicity right 5 radian/Evis [GeV] from 0.175 down to 0.05, constant above and below 30 Z’ limit Both CDF and DØ have Ztt measurements Stefan Grünendahl Tevatron Searches @ Aspen 2005

  14. Higgs Tevatron Production Current status (from precision EW fits): mH = 114 +69 –45 GeV mH < 260 GeV @ 95% CL Production cross section: ~1 pb for gg H ~0.1 pb for W,Z associated production Decay modes: mH < 140 GeV : bb above 140 GeV: WW* Higgs Decay Stefan Grünendahl Tevatron Searches @ Aspen 2005

  15. Leptons + jets: WHenbb DØ : 6 double b-tag events in 174 pb-1 spectra well described by SM • s(Wbb) < 6.6 pb (for PT(b)>20 GeV, DR(bb) > 0.75) • s(WH) < 9.0-12.2 pb (for MH=105-135 GeV) hep-ex/0410062 Stefan Grünendahl Tevatron Searches @ Aspen 2005

  16. WXenbb, mnbb (X=Higgs, Techni-pion) • 1-tag analysis for 162 pb-1 from CDF: Higgs and Technicolor limit Stefan Grünendahl Tevatron Searches @ Aspen 2005

  17. Higgs in multijets (high tan b) 2 tagged jets • DØ, based on 130 pb-1 • Higgs produced in association with 1 or 2 b • 3 b-tagged jets • limits on ‘down-type’ Higgs in models with more than one doublet (typically MSSM Higgs) 3 tagged jets Stefan Grünendahl Tevatron Searches @ Aspen 2005

  18. Leptoquark limits CDF: 200 pb-1 Leptons + jets, lepton + MET + jets, MET + jets combined Stefan Grünendahl Tevatron Searches @ Aspen 2005

  19. 1st gen.leptoquark • DØ: based on 252 pb-1 • No excess observed • hep-ex/0412029 Stefan Grünendahl Tevatron Searches @ Aspen 2005

  20. Leptons + jets: Technicolor Data, background and signal for theWenchannel • DØ: rT (Wen) + (pTbQ) (Q=b,c), based on 238 pb-1 s < 6.4 pb for m(rT)=200 GeV, m(pT)=105 GeV Stefan Grünendahl Tevatron Searches @ Aspen 2005

  21. Jets + MET • D0 leptoquark search, based on 85 pb-1 • 2 jets, one central, • pT1>60 GeV/c, • pT2>50 GeV/c, • MET > 70 GeV, • 35  < DF(MET,jet)<165 M(LQ) > 109 GeV/c2 QCD fit below 55 GeV CDF: 191 pb-1 M(LQ) > 117 GeV/c2 LQ efficiency Stefan Grünendahl Tevatron Searches @ Aspen 2005

  22. Monojets • D0 monojet search, based on 85 pb-1 (same trigger as LQ search) • one central jet, • pT1>150 GeV/c, • pT2<50 GeV/c, • pTem<10 GeV/c, • pTm<10 GeV/c (no isolated muon), • MET > 150 GeV, • DF(MET,jet)>30 Generator by Lykken and Matchev, based on [2] Result: Stefan Grünendahl Tevatron Searches @ Aspen 2005

  23. Monopoles • CDF search with special TOF trigger in 25 pb-1 • Large magnetic charge heavily ionizing • Accelerated along mag. field special GEANT version • Slow movinglate signals  small (10%) TOF acceptance loss for 900 GeV monopoles • Offline: Drift chamber verification via width of ionization pulse: cut far beyond standard particle range Stefan Grünendahl Tevatron Searches @ Aspen 2005

  24. Long-lived parent of Z0 • CDF dimuons from 163 pb-1 • Parent e.g. b’ with mb’<mt • Search for Z from offset vertex • Low eff * acceptance due to tracking requirement • 5 events observed; consistent with background (1 m-track misreconstructed) Stefan Grünendahl Tevatron Searches @ Aspen 2005

  25. Summary • Current results based on 0.25 fb-1 • More than 0.5 fb-1 on tape • Steady progress, not only due to more data, but also improvements in tools and methods (b –tagging, secondary vertex triggers) • World’s best limits on LQ, Z’, LEDs • Higgs: still an order of magnitude to go • Watch for updates for the rest of the winter conferences • http://www-cdf.fnal.gov/physics/exotic/exotic.html • http://www-d0.fnal.gov/Run2Physics/WWW/results.htm Stefan Grünendahl Tevatron Searches @ Aspen 2005

  26. Stefan Grünendahl Tevatron Searches @ Aspen 2005

  27. Measurement of Z+b/Z+jet • Important check of our understanding of b-yield and systematics for searches (e.g. ZH assoc.production) Taggable jets agree with MC within Jet Energy Scale (JES) uncertainty PT spectrum of B-tagged jets Transverse decay length significance of B-tagged jets result:s(Z+b)/s(Z+jet) = 0.023 ± 0.004(stat)+0.002 -0.003(syst) agrees well with NLO prediction (CTEQ5) of 0.018 ± 0.004 Stefan Grünendahl Tevatron Searches @ Aspen 2005

More Related