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Top Quark and W Boson Mass at CDF

Top Quark and W Boson Mass at CDF. Young-Kee Kim The University of Chicago Forth Workshop on Mass Origin and Supersymmetry Physics March 6-8, 2006 Tsukuba, Japan. x. x. x. x. x. x. x. x. x. x. x. Origin of Mass. There might be something (new particle?!) in the universe

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Top Quark and W Boson Mass at CDF

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  1. Top Quark and W Boson Mass at CDF Young-Kee Kim The University of Chicago Forth Workshop on Mass Origin and Supersymmetry Physics March 6-8, 2006 Tsukuba, Japan

  2. x x x x x x x x x x x Origin of Mass There might be something (new particle?!) in the universe that gives mass to particles. Nothing in the universe Something in the universe Higgs Particles: Coupling strength to Higgs is proportional to mass. Photon Electron Z,W Boson Top Quark x x Young-Kee Kim, Univ. of Chicago

  3. The importance of MW and Mtop Precision Electroweak Measurements probe the Higgs bosons indirectly by means of quantum corrections.

  4. Quantum Corrections • Large quantum corrections to Electroweak observables come from the top quark. top top top bottom W Z Different quantum corrections to MW and MZ With precision (better than ~1%) MW, MZ, cosW measurements, we can predict top quark mass. Young-Kee Kim, Univ. of Chicago

  5. Now Mtop: Measurements vs. Prediction Top Mass Prediction from the global fit to EW observables Direct measurements from CDF and D0 Limits from direct searches with e+e- and pp Young-Kee Kim, Univ. of Chicago

  6. Inputs: s, em(MZ2), MZ top bottom 80.5 80.4 80.3 W W 200 GeV 300 GeV Mhiggs = 100 GeV MW (GeV) 500 GeV 1000 GeV Higgs 150 175 200 Mtop (GeV) • For equal weights in 2 fits for MHiggs, • MW = 0.007 Mtop (Mtop = 2 GeV, MW = 14 MeV) Quantum Corrections • Secondary contributions are from the Higgs. MW= MW0 + C1 Mtop2 + C2ln(MHiggs2) Young-Kee Kim, Univ. of Chicago

  7. 80.5 80.4 80.3 MW (GeV) 5 Discovery Luminosity (fb-1) hard hard easy 150 175 200 100 200 300 500 800 Mtop (GeV) MHiggs (GeV) MW - Mtop - MHiggs Higgs Mass: Will the Tevatron’s prediction agree with what LHC measures? (LP’05) Young-Kee Kim, Univ. of Chicago

  8. Importance of MW and Mtop in MSSM Additional quantum corrections from SUSY partners (Summer 05) Higher precision MW and Mtop measurements will enable to distinguish between the Standard Model, Light SUSY, and Heavy SUSY Young-Kee Kim, Univ. of Chicago

  9. LEP2 95%CL SM Higgs Limit Mtop helps constraining MSSM models. Importance of Mtop in MSSM G. Degrassi, S.. Heinemeyer, W. Hollik, P. Slavich, G. Weiglein Eur. Phys. Jour. C28 (2003) 133, hep-ph/0212020 Mtop Mtop plays a key role in determining Mh in MSSM. Young-Kee Kim, Univ. of Chicago

  10. You should go to the masseslearn from them, andsynthesize their experienceinto better, articulated principles andmethods, …. - Mao

  11. Today LP’05 Tevatron Performance (Run II) Peak Luminosity Int. Lum. (delivered) / Experiment 2002 2003 2004 2005 2002 2003 2004 2005 shutdown • Peak luminosity record: 1.8  1032 cm-2 s-1 • Integrated luminosity • weekly record: 27 pb-1 / week / expt • total delivered: 1.5 fb-1 / expt, total recorded: 1.3 fb-1 / expt • Doubling time: 1 year • Future: ~2 fb-1 by 2006, ~4 fb-1 by 2007, ~8 fb-1 by 2009 Young-Kee Kim, Univ. of Chicago

  12. Tevatron Detectors CDF DZero Excellent Detectors - tracking, b-tagging, calorimeter, muon CDF Strength: momentum resolution and particle ID(K,) DZero Strength: muon coverage and energy resolution Young-Kee Kim, Univ. of Chicago

  13. Tevatron MW and Mtop Status in Lepton-Photon 2005 W Mass Top Mass Tevatron Run I (~110 pb-1) Tevatron Run I (~110 pb-1) + Run II (320-350 pb-1) Run I Young-Kee Kim, Univ. of Chicago

  14. q W, Z q g q e, e, e,  W Mass Measurements W Z

  15. _ p p J/ +- mass vs 1/pT p / p = - (0.10 ± 0.01)% 1 / pT(GeV-1) CDF Preliminary Data MC E(EM cal) p / p = - (0.03 ± 0.01)% p(tracking) e beampipe, silicon e E / p of W electrons +- mass (GeV) near Upsilon Lepton Momentum and Energy Scale • Understand passive material well: • Flatness of J/+-mass over a large pT range • E/p tail - data vs. simulation • MJ/ = 0.05 MeV MB = 0.2 MeV Young-Kee Kim, Univ. of Chicago

  16. Run II MW Status Run II W  e Run II W  Data MC W Transverse Mass [GeV/c2] W Transverse Mass [GeV/c2] Run II 200 pb-1 (Run Ib 90 pb-1) Integrated Luminosity [fb-1] MW [MeV] CDF Run II Young-Kee Kim, Univ. of Chicago

  17. W+ t t b q W- q b g q all jets: 44% : 21% b q q e+jets: 15% b ee,e,: 5% +jets: 15%  e/+jets is most powerful Large Br, 1 - better than dilepton Sig / Bgrnd - better than all jets B tagging Secondary vertex, Jet Prob., Soft e/ e+ ,  g g Top Mass Measurements

  18. Mtop Analysis Method: Template • Select jet-parton assignment that gives the best 2 for M(2 jets) = MW and M(top) = M(anti-top) • Reconstruct top mass • tt-bar MC “templates” with different Mtop values • background “templates” • data • Perform maximum likelihood fit to extract measured mass. Young-Kee Kim, Univ. of Chicago

  19. Mtop Analysis Method: Matrix Element • Originally proposed in 1988 by Kuni Kondo • J. Phys. Soc. 57, 4126 • For each event, • All jet-parton assignments are considered and weighted by comparing that to the leading order Matrix element calculation. • A probability distribution is produced. Each curve is a probability function from one Monte Carlo event. Young-Kee Kim, Univ. of Chicago

  20. Jet Energy Determination • Jet energy resolution • 84%/√ET • Statistical uncertainty • Jet energy scale • ~3% for jets from top decay • Dominant systematic uncertainty • New technique in Run II • In-situ calibration using W  2 jets mass in lepton+jets channel Young-Kee Kim, Univ. of Chicago

  21. Mtop in lepton+jets: Template (680 pb-1) Tsukuba group (Shinhong Kim, Taka Maruyama, Tomonobu Tomura, Koji Sato) has been playing key roles!! Young-Kee Kim, Univ. of Chicago

  22. Mtop in lepton+jets and dilepton Channels Lepton+jets Dilepton Template Matrix Element Mtop (template) = 173.4 ± 2.5 (stat. + jet E) ± 1.3 (syst.) GeV Mtop (matrix element) = 174.1 ± 2.5 (stat. + jet E) ± 1.4 (syst.) GeV Mtop (matrix element) = 164.5 ± 4.5 (stat.) ± 3.1 (jet E. + syst.) GeV Young-Kee Kim, Univ. of Chicago

  23. Mtop Uncertainty (Run II) CDF Run II Preliminary CDF Combined: MtopCDF = 172.0 ± 1.6 ± 2.2 GeV = 172.0 ± 2.7 GeV Young-Kee Kim, Univ. of Chicago

  24. Mtop in l+jets using Decay Length Technique • B hadron decay length  b-jet boost  Mtop • Difficult • Measure slope of exponential • But systematics dominated by tracking effects • Small correlation with traditional measurements • Statistics limited now • Can make significant contribution at LHC Mtop (Lxy) = 183.9 +15.7-13.9 (stat.) ± 5.6 (syst.) GeV Young-Kee Kim, Univ. of Chicago

  25. Other CDF Mtop results (318 - 360 pb-1 data through Aug. 04) • Three template-style analyses in dilepton channel • Combined result (340 - 360 pb-1) 170.1 ± 6.0(stat.) ± 4.1(syst.) GeV • Dynamical Likelihood method (Matrix Element) • Lepton+jets (318 pb-1) 173.2 +2.6-2.4(stat.) ± 3.2(syst.) GeV (Kohei Yorita’s Ph.D. Thesis) • Dilepton (340 pb-1) 166.6 +7.3-6.7(stat.) ± 3.2(syst.) GeV (Ryo Tsuchiya’s Ph.D. Thesis) 63 events joint likelihood All consistent with more recent measurements reported here. Young-Kee Kim, Univ. of Chicago

  26. Tevatron Top Mass Results Summer 2005 New since Summer 2005 Dilepton: CDF-II MtopME = 164.5 ± 5.5 GeV Lepton+Jets: CDF-II MtopTemp = 174.1 ± 2.8 GeV CDF-II MtopME = 173.4 ± 2.9 GeV CDF Combined: MtopCDF = 172.0 ± 1.6 ± 2.2 GeV = 172.0 ± 2.7 GeV Updated CDF + DØ combined result is coming! Young-Kee Kim, Univ. of Chicago

  27. MW [MeV] MTop [GeV] MHiggs / Mhiggs [%] 10-1 1 10 10-2 10-1 1 10 Luminosity / Experiment [fb-1] Luminosity / Experiment [fb-1] Luminosity / Experiment [fb-1] Electroweak Projections CDF Run II CDF Run II Young-Kee Kim, Univ. of Chicago

  28. Mtop = MtopRun I / √ LumRun II / LumRun We have been doing much better than we predicted. Data makes us smarter! Comments on Projections (e.g. Mtop) CDF Top Mass Uncertainties Run I Measured 110 pb-1 Run II (2fb-1) Projections in 1996 Run II Measured 318 pb-1 680 pb-1 Run II (8fb-1) Projections In 2005 Int. Lum [pb-1] Young-Kee Kim, Univ. of Chicago

  29. MW, Mtop and Mhiggs in Tevatron/LHC/ILC Young-Kee Kim, Univ. of Chicago

  30. Conclusions W Mass: 1st Run II meas. - coming soon (by this summer) - better than Run I Top Mass: MtopCDF = 172.0 ± 2.7 GeV/c2 (680 pb-1) CDF surpassed 2 fb-1 Run II goal of 3 GeV/c2 Significant improvements in analysis techniques Matrix element method, in situ jet energy calibration Tevatron measurements in the LHC era: By LHC turn-on, we expect Mtop~2 GeV, MW~30 MeV. By the end of this decade, Mtop~1.5 GeV, MW~20 MeV Comparable to LHC measurements Most likely be the best for quite some time. Higgs mass: Will Tevatron’s prediction agree with LHC’s direct measurement?

  31. BACKUP Young-Kee Kim, Univ. of Chicago

  32. MW Luminosity Effects Effects of higher instantaneous luminosity on uncertainty  Transverse Momentum W Transverse Mass e,  Lepton Transverse Momentum Young-Kee Kim, Univ. of Chicago

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