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CDF: Experimental Interests and Theoretical Issues.

CDF: Experimental Interests and Theoretical Issues. Ronan McNulty (University of Liverpool) on behalf of the UK CDF groups: Glasgow; Liverpool; Oxford; UCL. Explore areas of common interest between theorists/phenomenologists at IPPP and experimentalists at the Tevatron.

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CDF: Experimental Interests and Theoretical Issues.

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  1. CDF: Experimental Interests and Theoretical Issues. Ronan McNulty (University of Liverpool) on behalf of the UK CDF groups: Glasgow; Liverpool; Oxford; UCL.

  2. Explore areas of common interest between theorists/phenomenologists at IPPP and experimentalists at the Tevatron. • Shopping list of theoretical questions and desires • Brief Status of collider and detector • Concentrate on physics measurements that UK is involved in. (RAL status report http://hep.ph.liv.ac.uk/~mcnulty) • Highlight theoretical/phenomenological problems that we experimentalists see • Maybe we can compile a list of common topics and follow it up with more detailed discussions with relevant experts. Help!

  3. The Tevatron CDF D0 581 people 12 countries 580 people 17 countries - p-p collisions at sqrt(s) = 1.96 TeV

  4. Run 1 vs Run 2

  5. Run 1 Run 1 The Tevatron delivered • Run I: 120 pb-1 until 1996 • Run II: • Started March 2001 • 2 fb-1 by 2006 • 6.5 fb-1 by 2008 • Disappointing startup but have now exceeded Run I luminosity! • Peak luminosity increasing • Run I best: 2.8x1031 cm-2s-1 • Run II best: 3.5x1031 cm-2s-1 • Run II goal: 20 x1031 cm-2s-1 recorded Mar. 2001 Dec. 2002

  6. CDF XFT,SVT triggers

  7. CDF in Run II • Major upgrades • trigger/DAQ • Plug calorimeters • Silicon tracker • Tracking drift chamber • Started March 2001 • >100 pb-1 of good data by now CDF fully operational and taking high quality data

  8. Level 2 hadronic B trigger s(d0) ~ 48 mm 15 ms operation online primary vertex finding, tracking trigger on displaced vertices SVT Level 2 Trigger

  9. TOF Performance TOF resolution within 10 –20% of design value (100 ps) Calibration ongoing eg. f S/N = 1942/4517 TOF S/N = 2354/93113

  10. Physics programme at Run 2 # events in 1 fb-1 1014 1011 107 104

  11. Higgs

  12. Production and Decay of Higgs mH < 150 GeV: Look in qq->h(W/Z)->bbl(l/n) mH > 150 GeV: Look in gg->h->WW

  13. Higgs: Signal and Background rates Events / fb-1

  14. Expected Luminosity in Run 2 Expected Luminosity in Run 2 (updated) Discover m(H) ~120 GeV, exclude m(H) ~ 190 GeV Exclude m(H) ~130 GeV

  15. Diffractive Higgs -jet exclusive gap gap H p p -jet beam Reconstruct from missing mass of pp system p’ dipole roman pots dipole p’ 25-30 GeV mass resolution standard method, ~ 0.5 GeV resolution diffractive mode roman pots

  16. Higgs s small @ Tevatron, reasonable at LHC Signal (Cudell, Hernandez) Background

  17. Diffractive Higgs Subject of Durham Workshop 20th Sept 2001 Theoretical Models Khoze, Martin & Ryskin Cox, Forshaw, Heinemann Boonekamp, Peschanski, Royon Experimentally Relate to p+g+g+p

  18. hopeless? observable prediction normalisation Predict diffractive H Diffractive Higgs POMWIG (works at Hera) Scale to fit CDF diffractive di-jet Predict diffractive gg LHC 2.8/fb 1.3/fb Cox, Forshaw, Heinemann, Phys.Lett.B540 (2002)

  19. Diffractive Higgs: Competitive channel at LHC 30 fb-1 at LHC DeRoeck, Khoze, Martin, Orava, Ryskin Eur.Phys.J.C25:391-403,2002

  20. Diffractive Higgs: Experimental Status All predictions tested by just one run I measurement of dijet-production: σ(inel.)=44+-20 nb σ(excl.)<3.7 nb at 95% C.L. exclusive CDF Run I data - Higgs mass reconstruction only possible in exclusive channel but not yet observed experimentally - Prediction (KMR): σ≈1nb => Run II

  21. Diffractive Higgs: Measurements at the Tevatron Boonekamp, Peschanski, Royon hep-ph 0301244 Exclusive Prediction?

  22. W

  23. Tag W by decay to hard isolated e,m Calorimetry scale set by Z, resonances (J/y) Obtain m(W), G(W) from transverse mass fit Electroweak: W mass and width With 2 fb-1: s(W), s(Z)  12 % m(W) measured to 40 MeV (sys. dominated - theory) G(W) measured to 30 MeV couplings measured to ~0.3

  24. W candidates W->en W->mn 4561 candidates in 16 pb-1 5547 candidates in 10 pb-1

  25. Z candidates Z->mm Z->ee m1 m2 247 candidates in 10 pb-1 57 candidates in 16 pb-1

  26. Electroweak: m(W) errors

  27. pp -> W -> ln Production: QCD Mirkes et al. NLO: DmW = 40MeV smW ~ 10MeV Decay: EW Baer et al. NLO: DmW = 100s MeV smW~ 20MeV Factorisable? O(aSaem) calculation? How to test?

  28. Di Boson

  29. Background to Higgs mH<150 GeV: Bkg is WZ or ZZ mH>150 GeV: Bkg is WW “Standard Candle” mH < 150 GeV: qq->h(W/Z)->bbl(l/n) mH > 150 GeV: gg->h->WW DiBoson Production Probe EW structure Anomalous couplings Background to top/many SUSY searches. We have QCD NLO for WZ->lnll ?? WZ -> lnbb ??

  30. MCFM(NLO) not interfaced to PS MCFM(NLO) MCFM(LO) + Pythia NLO ok MC@NLO MC@NLO PS ok MC@NLO doesn’t simulate width/spin. MCFM(NLO) need to be interfaced to PS MCFM LO only Examine production rates and angular distributions of Wγ, Zγ, WW, WZ, ZZ, and γγ (Not fully understood Run1) DiBoson Production No spin correlations Need PS + NLO with spin + Gw

  31. Di-Photon Production • Sensitive to New Physics Scenarios: • Cascade decays of heavy new particles producing gg + Et + l/W/Z/g/jets/b-jets • Large Extra Dimensions: • Graviton exchange contributes • Present sensitivity about 900 GeV • Run II sensitivity: 2 TeV • Generic “bump” search, e.g. fermiophobic higgs

  32. What could it be? Hint of NP? What other signals suggested?

  33. Top

  34. # events in 1 fb-1 1014 1011 107 104 Top: Production Mechanism Quark annihilation Gluon Fusion s(tt) +40%, Lumi x20, btag+60% Factor 3 improvement mt, stt + original physics measurements 100 200 Higgs Mass

  35. top decays before hadronisation! Decay Mechanism 2/3 : 1/3 3 : 3 : 1 : 1 : 1 t b Space W Time Top Quark is a Free Quark ttop = 1/Gtop = 5x10-25 sec < 1/LQCD

  36. 1/9 4/9 4/9

  37. Lepton + Jet Mode Accurate background MC req’d, particularly W+4jets

  38. Hadronic Mode (6 jets) Accurate background calculation vital qqqqbb

  39. Leptonic Mode

  40. Is it a Standard Model Top? Can it be a probe for New Physics? Can it tell us about the Higgs? Check s, mass, spin, Lefthandedness, CKM matrix, Single Top Electroweak Fits Any deviations from SM? New effects at the EWSB scale? SUSY? Technicolour, FCNC, New resonances, H+ Physics of Top

  41. Run II Error Is it a Standard Model Top • Does the cross-section agree with QCD? • Does the mass agree with SM • Are decays as expected? Count e, m,t, jets, b-jets. • Check kinematics: pT & angular distributions

  42. W Polarisation, Vtb, Top Spin G(t->Wb) = Vtb2G(t->X) CDF: |Vtb| > 0.76 (95%cl) CDF measure F0=0.91+-0.39 .88 in SM D0 measure k>-0.25 @68%cl.

  43. .88pb 2.4pb Vtb from Single Top s(qq->tb) G(t->W+b) Vtb2 Indirect measure of top lifetime Clear observation dependent on accurate background MC Single Top not yet seen

  44. Probe for new physics Non SM production X->tt Non SM decay t->Xb Resonances in tt production Topcolour: qq->V->tt Technicolour: qq->hT->tt In some models tt condensate explains large top mass/EWSB SUSY stop: t->t+c0 & t->b+l+v gluino -> stop + top SUSY Higgs t->b + H+ => enhanced t s. Z’ New Physics ~ Top as Probe for NP. Unique role of heavy quark Top unique to Tevatron

  45. Run 2 Dr is fn of Da mtop2(few%) ln(mH) (<%) Direct Measurement agrees with Radiative Prediction and favours light Higgs mt

  46. W + Njets Background Background in lepton+jet mode from W+Njets There are NLO calculations for +1,+2 but not(?) +3, +4 Current theory v experiment not fantastic Highest E jet 2nd Highest E jet Help us understand W+Njets NLO calculations?

  47. New Physics

  48. New Physics • SM breakdown at ~1TeV • SUSY is ‘just around the corner’ • Tantalising Hints from Run1 eeggEt High Et excess

  49. Inclusive Central Jet Cross Section Data over ~7 orders of magnitude Run1a and 1b results consistent .. Observed deviation in tail …….. is this a sign of new physics ?

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