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New Physics Searches at the Tevatron

New Physics Searches at the Tevatron. Amitabh Lath Rutgers University/CDF For the CDF and D0 Collaborations ICHEP 2004 Beijing. CDF. D0. Chicago! .  p. p. 1.96 TeV. Booster. p. CDF. DØ. Tevatron.  p. p sou rce. Main Injector & Recycler.

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New Physics Searches at the Tevatron

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  1. New Physics Searches at the Tevatron Amitabh Lath Rutgers University/CDF For the CDF and D0 Collaborations ICHEP 2004 Beijing CDF D0

  2. Chicago!  p p 1.96 TeV Booster p CDF DØ Tevatron p p source Main Injector & Recycler Tevatron: The Energy Frontier • 1.96 TeVCM Energy • 500 pb-1 to tape NOW • 4 fb-1 to tape by FY 2009. (8 fb-1 possible?) • When will new physics show up? • What will it look like? • Will our triggers and analyses be sensitive to it? We need to think beyond established theories

  3. New Physics:Beyond Higgs, SUSY • Use familiar objects: e, m, t, g, jet, ET • Massive Objects: • Z’/W’, Gravitons (leptons, photons) • Leptoquarks (leptons, ET , jets) • Extra dimensions (leptons, jets, ET) • Compositeness: • Excited Fermions (leptons, photons) • Technicolor (leptons) • Truly Exotic Objects • Charged Massive Particles (CHAMPS) • Magnetic Monopoles

  4. The Classic Searchese+e-: Probe Z’, RS Graviton… D0 Run II 200 pb-1 D0 Hypothetical Z’ Large Extra dimensions Note: agreement over 2 orders of magnitude in mee.

  5. The Classic Searchescontinuedm+m- : Probe Z’, RS Graviton… D0 250 pb-1 D0 100 pb-1 e,m complimentary: euses EM calorimeter, resolution better at harder e. muses tracker, resolution better at softer m.

  6. Typical High Mass events. CLEAN! CDF D0 Historically ee, (mm) searches have paid off handsomely at hadron machines. Insensitive to QCD remnants.

  7. Dilepton Cross-Section Limits: ee D0 D0 200 pb-1 CDF :Z’ee Limit 750 GeV/c2 LIMITS ~50 fb D0:Z’ee Limit 780 GeV/c2

  8. Dilepton Cross-Section Limits:mm D0 250 pb-1 LIMITS ~60 fb CDF :Z’mm Little Higgs (cotq=0.7) 720 GeV/c2 D0 :Z’mm (SM) > 680 GeV/c2

  9. Technicolor: Almost there! Need another order of magnitude

  10. Another promising channel: Diphoton g an e without a track. LIMITS ~70 fb

  11. Combined Limits: Graviton, LED • Pairs of hard, isolated leptons and photons are powerful tools to hunt new physics. • The SM backgrounds • are small and well understood. • The results are s*BR, which can be interpreted in a variety of ways by different models (some of which haven’t been published yet!) D0 Extra dimensions D0 h = F/Ms4 h limit:0.24 TeV-1 MPL>1.43 TeV (GRW) World’s best limit on MPL

  12. Adding ET : W’ Search • Electron + ET • Neutrinos show up as MET • Many sources of ET tails: • Muons • Cracks in detector • Energy calib. • Plot shows we have good understanding of ET. W’ limit plot work in progress.

  13. e+g: Compositeness (Excited electrons) 3 events seen contact meg Gauge mediated Electron + g

  14. Limits on excited electrons Gauge LIMITS ~70 fb

  15. Electrons+Jets: Leptoquarks D0 Two energetic electrons. Two jets 1st gen. LQ D0 Scalar Energy sum, eejj

  16. b=1 Electrons+Jets: Leptoquarks Two energetic electrons. Two jets • Limit ~ 100 fb • More challenging at lower mass. • QCD bg requires hard cuts that affect limit at low mass. • Jets harder to study than e, g • Jet multiplicity hard to simulate. • Jet quark, g correspondence hard to disentangle • Jet energy resolution not nearly that of e, g. D0 238 GeV/c2

  17. Electron+Jets+ET: Leptoquarks • One energetic electron. • ET • Two jets b is BR(LQeq) =0.5 Limit ~ 100 fb D0 197 GeV/c2

  18. Jets + ET: Leptoquark No electrons in final state Leptoquark goes to n, jet. Challenging at low mass. Important for squark/gluino searches

  19. Leptoquarks (1st Gen. Limits) D0 200 pb-1 D0

  20. Now with m: LQ 2nd Generation Two muons, Two jets. Limit ~ 70 fb

  21. Jets+MET:Large Extra Dimensions D0 D0 D0 QCD Most stringent No k factor D0 Number of Dimensions Need to understand calorimetry, tracking, acceptance in excruciating detail.

  22. A special sort of jet: thadrons LIMITS ~1000 fb See Weiming Yao’s talk for more on taus

  23. Truly Exotic: CHAMPS • CHAMPS are slow moving • Large Ionization loss • Long time of flight • Highly penetrating • Will look like a muon misolated-stop > 108 GeV/c2 CHAMP LIMITS ~10,000 fb

  24. Truly Exotic: Monopole • Bends in the wrong plane( high pt) • Large ionization in scint (>500 Mips!) • Large dE/dx in drift chamber TOF trigger designed specifically for monopole search mmonopole > 350 GeV/c2 LIMITS ~300 fb

  25. Summary • Tevatron luminosity is ramping up. • 4 fb-1 promised by 2009. Exciting physics possible. • Translating detector understanding to physics. • Objects like e, m, g, t, ET, jets, (b) are now reconstructed w/ excellent efficiency, purity. We use these to search for V’, Technicolor, LQ, excited fermions, extra dim... • Going to get even better: More luminosity, better understanding. • Now, limits ~50 - 100 fb (leptons, photons). Soon, ~10 fb! • We think outside the box. • Hunt for new objects like CHAMPS, monopoles… • Could use help from theorists here. • We hope to see new physics soon. We are sick and tired of making exclusion plots!

  26. Backup slides

  27. 12 pb-1 / week currently: above “design” 4 fb-1 line : 2009? Earlier? Aug04: ~0.7fb-1 delivered: > design Start of Fiscal Year Oct 03 TevatronPromises High Luminosity… Slam dunk!

  28. But can they deliver? Recent news is encouraging! Run 1 Last 30 weeks

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