1. The Latest Results of the CDF Experiment Kazuhiro Yamamoto (Osaka City University) For the CDF Collaboration March 26, 2007 JPS Meeting at Tokyo Metropolitan University

2. CDF Experiment Being performed at Tevatron accelerator in Fermilab. Proton-antiproton collision at  s = 1.96 TeV. Run II operation started in March 2001.

3. Tevatron Accelerator Main Injector Tevatron CDF DØ SciBooNE

4. CDF II Detector

5. Tevatron Status Accelerator performance –Growing year by year Typical parameters –Peak luminosity 2.0 ～ 2.5 x 10 32 cm -2 s -1 –Weekly integrated lum. 40 pb -1 /wk Run II record 2.923 x 10 32 cm -2 s -1

6. Tevatron Status (2) Integrated Luminosity

7. CDF Collaboration ~700 physicists from 12 nations and 61 institutions McGill Univ. Univ. of Toronto Argonne National Lab. Baylor Univ. Brandeis Univ. UC Davis UC Los Angeles UC San Diego UC Santa Barbara Carnegie Mellon Univ. Univ. of Chicago Duke Univ. Fermilab Univ. of Florida Harvard Univ. Univ. of Illinois The Johns Hopkins Univ. LBNL MIT Michigan State Univ. Univ. of Michigan Univ. of New Mexico Northwestern Univ. The Ohio State Univ. Univ. of Pennsylvania Univ. of Pittsburgh Purdue Univ. Univ. of Rochester Rockefeller Univ. Rutgers Univ. Texas A&M Univ. Tufts Univ. Wayne State Univ. Univ. of Wisconsin Yale Univ. JINR, Dubna ITEP, Moscow Univ. Karlsruhe Univ. of Geneva Glasgow Univ. Univ. of Liverpool Univ. of Oxford Univ. College London Univ. of Bologna, INFN Frascati, INFN Univ. di Padova, INFN Pisa, INFN Univ. di Roma, INFN INFN-Trieste Univ. di Udine IFAE, Barcelona CIEMAT, Madrid Univ. of Cantabria LPNHE, Paris KHCL KEK Okayama Univ. Osaka City Univ. Univ. of Tsukuba Waseda Univ. Academia Sinica USA Canada Russia Germany Switzerland UK Italy Spain France Korea Japan Taiwan

8. Top quark pair production Top quarks are mainly produced in pairs via strong interaction. Top quark decay –  ~ 10  24 sec, t  Wb (~100%) –W decays determine experimental signature ・ di-lepton :2 jets(2b) + 2 leptons + 2 neutrinos~ 5% ・ lepton + jets :4 jets(2b) + 1 lepton + 1 neutrino~30% ・ all-jets :6 jets(2b)~44%  

9. Top quark pair production (2) Cross section measurement –Dilepton : clean but small stat. –Lepton + jets : fairly good S/N and stat. –All jets : large stat. but poor S/N New approach in dilepton channel Lepton (e/  ) + isolated-track - increase acceptance - include  decays (to hadrons) No discrepancy to the SM was found yet.  (tt) = 9.0  1.3(stat)  0.5(syst)  0.5(lum) pb (L = 1070 pb -1 )

10. Top mass measurement Template method –Evaluate a variable strongly correlated with m t –Compare data to MC with different m t inputs Matrix Element method –Event likelihood by signal and background probability density –Maximum likelihood to fit m t, JES(jet energy scale, and C s (signal fraction) PDF Transfer function

11. Top mass measurement (2) Lepton + Jets channelAll hadronic channel m t = 170.9  2.2(stat+JES)  1.4(syst) GeV/c 2 = 170.9  2.6 GeV/c 2 m t = 171.1  3.7(stat+JES)  2.1(syst) GeV/c 2 = 171.1  4.3 GeV/c 2 At lesat 6 jets with E T > 15GeV |h|<2 Good jet shape (Centrality, Aplanarity)  1 b-tags E T > 280GeV Lepton E T (P T ) > 20GeV Jet E T > 15GeV Missing E T > 20GeV 1 b-tags QCD di-jet veto (0.5 <  < 2.5)

12. Top mass measurement (3) Future prospect –Uncertainty of <1% in the next years. We reached a precision of 1.1% in m t.

13. Single top production Top quark production via electroweak process.  One of the best tests for the standard model  Sensitivity to beyond the SM processes (FCNC, W’, 4 th family, …) Direct measurement of  V tb   Unitarity test of CKM matrix Important background of Higgs search  Same final state as that of WH  Wbb s-channel  NLO = 0.88  0.11 pb t-channel  NLO = 1.98  0.25 pb Phys. Rev. D70, 114012 (2004)

14. Single top production (2) Likelihood function analysis i :  indexes input variable Neural network analysis Matrix element analysis Single top hidden behind background uncertainty  Makes counting experiment difficult t-channel s-channel Still need a little more statistics

15. Single top production (3) DØ declared “evidence”. –Analyses using Boosted decision trees, Matrix elements, and Bayesian neural networks Combined result :  s+t = 4.9  1.4 pb (3.4  significance) hep-ex/0612052

16. Electroweak diboson production According to the SM, only WW  and WWZ vertices are allowed. Precise measurement of each coupling is one of the sensitive tests to the SM.  Window of new physics Multi-lepton final states are major background sources of Higgs, SUSY, and other exotics. EW diboson production gives information on trilinear gauge couplings.

17. W W production Two high-p T leptons and E T Mode WW 52.4  0.1  4.3 Drell-Yan 11.8  0.8  3.1 W + jets 11.0  0.5  3.2 WZ + ZZ 7.9  0.0  0.8 WW 6.8  0.2  1.4 t 0.2  0.0  0.0 Sum Background 37.8  0.9  4.7 Number of Expected 90.2  0.9  6.4 Number of Observed95,  (WW) = 13.6  2.3(stat.)  1.6(syst.)  1.2(lum.) pb NLO calculation :  (WW) = 12.4  0.8 pb hep-ex/0605066

18. W  Z  production W    channel Z   ee  channel  (W  )Br(W  ) = 19.1  1.0(stat.)  2.4(syst.)  1.1(lum.) pb NLO :  (W  )Br(W  ) = 19.3  1.4 pb  (Z  )Br(Z  ee) = 4.9  0.3(stat.)  0.3(syst.)  0.3(lum.) pb NLO :  (Z  )Br(Z  ) = 4.7  0.4 pb A. Nagano (U. of Tsukuba) et al.

19. Observation of WZ production Decays W  and Z  provide trilepton signature. CDF Observed 5.9  signal  1.8  (WZ) = 5.0 (stat. + syst.) pb  1.6 NLO calculation :  (WZ) = 3.7  0.3 pb First observation of WZ production

20. Search for Z Z production Four charge-balanced leptons from Z 0 Z 0       (ZZ) < 3.8 pb (95% C.L.) Z 0 Z 0  e  /         candidate SM NLO calculation :  (ZZ) = 1.4  0.1 pb

21. W mass measurement m W : fundamental constant as well as m t in SM and BSM Radiative corrections strongly correlated to Higgs mass Summer ’06

22. W mass measurement (2) Determine m W by comparing transverse mass ( m T ) b/w data and MC. Charged-lepton track calibration –Cosmic, J/ , , Z  Calorimeter E T calibration –E/p, Z  ee Hadronic recoil correction –p T balance in Z  QED effects p T distribution tuning Parton distribution Charged-lepton track calibration –Cosmic, J/ , , Z  Calorimeter E T calibration –E/p, Z  ee Hadronic recoil correction –p T balance in Z  QED effects p T distribution tuning Parton distribution

23. W mass measurement (3) Transverse mass spectra W  e channel W   channel

24. W mass measurement (4) Charged lepton E T (P T ) Missing E T (Neutrino P T )

25. W mass measurement (5) Transverse mass fit uncertainties (MeV) electronsmuonscommon Statistics4854 Lepton energy scale3017 Lepton resolution933 Recoil energy scale999 Recoil energy resolution777 Selection bias310 Lepton removal855 Backgrounds890 p T model tuning333 PDF11 QED corrections111211 Total systematic392726

26. W mass measurement (6) Fits to m T, p T, E T, and combine them all. mTmT p T ETET Comb. fitstat.syst.fitstat.syst.FitStat.Syst. e804934839804515845804735754 80477  62  803495427803216640803966646 80352  60 Common263542 Comb. 80417  4880388  5980434  65 m W (total comb.) = 80413  48 MeV/c 2

27.   33 SM Higgs mass : 76 GeV/c 2  24 SM / MSSM comparison hep-ph/0604147 and references are therein. W mass measurement (7) New CDF result is the world’s most precise single measurement. World average uncertainty reduced ~15% EW global fit : Blue band m H < 144 GeV/c 2 @ 95% C.L.

28. Observation of B s 0 Oscillation  m s = 17.77  0.10(stat.)  0.07(syst.) ps  1 Please see PRL97 242003 and slides of JPS-DPF2006 for the detail. http://www.phys.hawaii.edu/indico/contributionDisplay.py?contribId=743&sessionId=218&confId=3 5  measurement of B s 0 -B s 0 oscillation !

29. Observation of  b  and  b *  So far,  b (udb) was the only established b-baryon. Next accessible baryon :  b  b  (uub, J=1/2),  b  (ddb, J=1/2)  b *  (uub, J=3/2),  b *  (ddb, J=3/2) J=1/2 J=3/2

30. Observation of  b  and  b *  (2) Reconstruction of the decay chain:   2.0 m(  b  ) = 5808 (stat.)  1.7(syst.) MeV/c 2  2.3  1.0 m(  b  ) = 5816 (stat.)  1.7(syst.) MeV/c 2  1.0  1.6 m(  b *  ) = 5829 (stat.)  1.7(syst.) MeV/c 2  1.8  2.1 m(  b *  ) = 5837 (stat.)  1.7(syst.) MeV/c 2  1.9  b ( * )    b 0 +    c + +   p + K  +   L b 0 reconstruction Signals consistent with lowest lying  b  states at > 5  significant level.

31. Search for Higgs boson SM Higgs boson at the Tevatron High mass Higgs (130 ~ 200 GeV/c 2 ) –WW dominant  multi-lepton signature Low mass Higgs (< 130 GeV/c 2 ) –bb dominant  reconstruction of 2b jets –gg  h  bb swamps on QCD background –Vh production is promising gg  h  WW    qq’  Wh  WWW *    X qq  Zh  ZWW *     X qq’  Wh  bb, qq’ bb qq  Zh    bb, bb, qq bb

32. Search for Higgs boson (2) Recent progress : Zh  bb High-p T opposite-sign dilepton 76GeV < M < 116GeV N jets  2 At least 1 b-tag Fit 2D-ANN outputs to extract possible signal fraction. Single b-tag Double b-tag Single b-tag Double b-tag

33. Search for Higgs boson (3) Recent progress : gg  h  WW  High-p T opposite-sign dilepton Isolated tracks Large Missing E T N jet  1 Used Matrix Element calculation to extract possible Higgs signals.  lim /  SM ~ 3 at M h ~160GeV/c 2

34. Search for Higgs boson (4) Combined Result (1 fb -1 ) Recent progresses presented in the previous slides are not included in this plot. Contribution of Japanese institutes  WH  l bb (Univ. of Tsukuba, Waseda Univ.)  WH  WWW (Osaka City Univ.) Updates coming soon … CDF Combination Summer ’06 Tevatron Combination

35. Summary The Tevatron collider and detectors (CDF and DØ) are running in pretty good shape ! 2.2 fb -1 has been recorded and ~1.1fb -1 was analyzed. –Some of the latest results were presented. Tevatron Run II is scheduled to continue till the end of FY2009, and 6~8fb -1 of integrated luminosity is expected to be obtained. –Can we see any signs of Higgs/SUSY before LHC ?