1. Electroweak and Related Physics at CDF Tim Nelson Fermilab on behalf of the CDF Collaboration DIS 2003 St. Petersburg April 2003

2. T. Nelson, DIS 2003 - Slide 2 Outline Experimental Status Electroweak Top Precision Searches Outlook

3. T. Nelson, DIS 2003 - Slide 3 Upgrades: E CM : 1.8  1.96 TeV E CM : 1.8  1.96 TeV Luminosity: 10 31  10 32 Luminosity: 10 31  10 32 Run 2b (396 ns) Run 2b (396 ns) Making progress… Currently less data approved for analysis than Run I 72 pb -1 72 pb -1 57 pb -1 w/ silicon 57 pb -1 w/ silicon Tevatron Status Luminosity [particles/cm 2 /s] Run 1b Current 2a Goal Run 2b

4. T. Nelson, DIS 2003 - Slide 4 The CDF-II Detector Silicon Tracking Detectors Central Drift Chamber Solenoid Coil /TOF EM Calorimeter Hadronic Calorimeter Muon Drift Chambers Muon Scintillator Counters Major Upgrade: New Silicon Tracking New Silicon Tracking Extended coverage 3-D reconstruction New Drift Chamber New Drift Chamber Faster (2  s  396 ns) dE/dx 96 dE/dx samples/track New Forward Calorimeter New Forward Calorimeter 1.3 <|  |<3.5, same technology as central Added Time-Of-Flight Added Time-Of-Flight ~ 100 ps resolution Extended muon coverage Extended muon coverage |  | < 1  |  |<1.5 New Trigger New Trigger Tracks at L1 (p T >1.5 GeV/c) Silicon Tracks at L2 (p T >2.0 GeV/c)

5. T. Nelson, DIS 2003 - Slide 5 Tracking Upgrades Tracking is fundamental to lepton identification   = - ln ( tan (  /2)) “central”:|  | < 1.1 “forward”: |  | > 1.1

6. T. Nelson, DIS 2003 - Slide 6 Silicon Upgrade SVX Layer 00 SVXII ISL Run I Run 2a Silicon tracking is fundamental to tagging b -jets  = - ln ( tan (  /2)) tt  e+jets

7. T. Nelson, DIS 2003 - Slide 7 Precision Electroweak (2 fb -1 ) Must walk before we can run!

8. T. Nelson, DIS 2003 - Slide 8  W  B ( W  e ) Selections : ( acc   = 19.3% ) Electron (central only) – Isolated EM Calorimeter cluster – E T > 25 GeV – Matched track, P T > 10 GeV Missing E T > 25 GeV Sample : ( 72 pb -1 Run II) 38628 events – QCD: 3.5% – W   : 2.0% – Z  ee : 0.9%  W  B = 2.64  0.01 stat  0.09 sys  0.16 lum nb

9. T. Nelson, DIS 2003 - Slide 9  W  B ( W   ) Selections : ( acc   = 10.1% ) Muon (central only) – Muon hits – Matched track, P T > 20 GeV – Min. Ionization in calorimeter Missing E T > 20 GeV Cosmic & Z   vetos Sample : ( 72 pb -1 Run II) 21599 events – Z   : 5.3% – W   : 3.2% – Cosmics: 1.3% – QCD: 1.0%  W  B = 2.64  0.02 stat  0.12 sys  0.16 lum nb

10. T. Nelson, DIS 2003 - Slide 10  W  B ( W   ) Selections : ( acc   = 0.92% ) Tau (central only) – Isolated Hadronic Calorimeter cluster – P T & number of tracks in 10  /30  cones – E T > 25 GeV Missing E T > 25 GeV Dijet veto Sample : ( 72 pb -1 Run II) 2345 events – QCD: 15% – W  e : 4.4% – W   : 3.9% – Cosmics: 1.5% – Z   : 0.9%  W  B = 2.62  0.07 stat  0.21 sys  0.16 lum nb

11. T. Nelson, DIS 2003 - Slide 11  Z  B ( Z  ee ) Selections : ( acc   = 9.5% ) 2 Electrons (central only) – Isolated EM Calorimeter clusters – E T > 25 GeV – Opp-sign matched tracks, P T > 10 GeV 66 < M ee < 116 GeV Sample : ( 72 pb -1 Run II) 1830 opposite-sign events – QCD: 0.5% – Z   : 0.05%  Z  B = 267  6 stat  15 sys  16 lum pb

12. T. Nelson, DIS 2003 - Slide 12  Z  B ( Z   ) Selections : ( acc   = 9.2% ) 2 Muons (central only) – At least one with muon hits – Opp-sign matched tracks, P T > 20 GeV – Min. Ionization in calorimeter Cosmic veto 66 < M ee < 116 GeV Sample : ( 72 pb -1 Run II ) 1631 opposite-sign events – Cosmics: 0.8% – QCD:< 0.2%  Z  B = 246  6 stat  12 sys  15 lum pb

13. T. Nelson, DIS 2003 - Slide 13 Clear Z   e  h signal Background needs further study Goal of preliminary cross section by summer Z   

14. T. Nelson, DIS 2003 - Slide 14  W,  Z Summary combined  W  B ( W  l ) = 2.640 ± 0.012 stat ± 0.093 syst ± 0. 158 lum nb combined  Z  B ( Z  ll ) = 251.5 ± 4.3 stat ± 10.6 syst ± 15.1 lum pb

15. T. Nelson, DIS 2003 - Slide 15  W   B ( W  e,  ) Selections : Electron or Muon (central only) + Missing E T – Same selections as used for  W 1 Photon (central only) – E T > 7 GeV,  R ( ,l ) > 0.7 * – Isolated EM calorimeter cluster – Tracking isolation cuts Z  ll & Cosmic(  ) vetos Sample : ( 72 pb -1 Run II) 43 (38) events in e (  ) – W  e (  ) + jet : 11.5 (5.6) events – Z  ee (  ) +  : 2.4 (5.1) events – W   +  : 0.5 (0.7) events  W  ( W  e ) * = 17.2  3.8 stat  2.8 sys  1.0 lum pb  W  ( W   )* = 19.5  4.5 stat  2.4 sys  1.2 lum pb SM Expected: ~19 pb e+ 

16. T. Nelson, DIS 2003 - Slide 16  Z   B ( Z  ee,  ) Selections : 2 Electrons or Muons (central only) – Same selections as used for  Z M ll > 40 GeV 1 Photon (central only) – E T > 7 GeV,  R ( ,l ) > 0.7 * – Isolated EM calorimeter cluster – Tracking isolation cuts Z  ll & Cosmic(  ) vetos Sample : ( 72 pb -1 Run II) 11 (14) opposite-sign ee (  ) events – Z  ee (  ) + jet : 0.5 (0.5) events  Z   B ( Z  ee )* = 5.5  1.7 stat  0.6 sys  0.3 lum pb  Z   B ( Z   )* = 6.0  1.6 stat  0.7 sys  0.4 lum pb SM Expected: ~5 pb e+ 

17. T. Nelson, DIS 2003 - Slide 17 Adding Forward Acceptance QCD backgrounds are many times larger without tracking requirements Tracking is critical Have standalone silicon tracking in forward region: much less efficient and clean than central drift chamber + silicon Need a way to reduce the problem!

18. T. Nelson, DIS 2003 - Slide 18 Calorimeter-seeded e  tracking Two points and a curvature define a unique helix… Primary vertex – x-y : beamspot (~40 um) – z: event vertex (~100 um) Calorimeter shower-maximum hit – ~1 mm Calorimeter E T  |curvature| seed tracks Silicon hits Silicon Track

19. T. Nelson, DIS 2003 - Slide 19 Forward W  e Selections : Electron (forward only) – Isolated EM Calorimeter cluster – E T > 20 GeV – Calorimeter-seeded track Missing E T > 25 GeV Sample : ( 60 pb -1 Run 2 data) ~20,000 events QCD background : without forward tracking: ~18% with forward tracking: ~3% Similar to central background

20. T. Nelson, DIS 2003 - Slide 20 W  e Charge Asymmetry x = p (parton)/ p (proton) pdf(x) u d Forward tracking is critical here!

21. T. Nelson, DIS 2003 - Slide 21 W  e Charge Asymmetry Selections : Electron (central+forward) – Isolated EM Calorimeter cluster – E T > 20 GeV – Calorimeter-seeded track Missing E T > 30 GeV Sample : 21317 events Blind analysis: Plotting sensitivity only Higher “specific sensitivity” in forward region than Run 1 results to be unblinded for summer CTEQ-3M - MRS-R2

22. T. Nelson, DIS 2003 - Slide 22 Selections : 2 Electrons / Muons (central only) – Same cuts as EWK measurements Veto 76 < M ll < 106 GeV, cosmics & conversions Missing E T > 25 GeV   ( missing E T, nearest lepton ) N jets = 0 ( E t > 10 GeV,  < 2.0) Sample : ( 72 pb -1 Run II) 2 events – Background: 1.5  0.6 events ( QCD + DY + WZ + tt ) SM Expected: 2.8  0.6  WW ( WW  ll ) just the appetizer…

23. T. Nelson, DIS 2003 - Slide 23  tt ( tt  ll ) Selections : 2 Electrons / Muons (central only) – Same cuts as EWK measurements Veto 76 < M ll < 106 GeV, cosmics & conversions Missing E T > 25 GeV   ( missing E T, nearest lepton ) H T =  E T + Missing E T > 200 GeV N jets  2 ( E t > 10 GeV,  < 2.0) Sample : ( 72 pb -1 Run II) 5 events – Background: 0.30  0.12 events ( DY + WW/WZ +  + QCD )  tt =13.2  5.9 stat  1.5 sys pb

24. T. Nelson, DIS 2003 - Slide 24  tt ( tt  l+jets ) Selections : Electron / Muon (central only) – Same cuts as EWK measurements Veto 76 < M ll < 106 GeV, cosmics and conversions Missing E T > 20 GeV N jets  3 (jet E T > 15 GeV) At least one jet with secondary vertex tag from silicon Sample : (57.5 pb -1 Run 2 data) 15 events – Background: 3.8  0.5 events (W+jets & mistags dominant)  tt = 5.3 ± 1.9 stat ± 0.8 syst pb signal region control region

25. T. Nelson, DIS 2003 - Slide 25  tt Summary Run II

26. T. Nelson, DIS 2003 - Slide 26 M t ( l+jets ) signal background

27. T. Nelson, DIS 2003 - Slide 27 Electroweak-related Searches A Challenging Goal : Model-independent, “signature-based” searches Focus on Final States : Many possibilities for new physics Very simple Backgrounds are “precision physics” “Precision Searches” Electroweak final states are ideal here…

28. T. Nelson, DIS 2003 - Slide 28 Z, extra dimensions, compositeness High-mass e + e - ? ? central-central + central-forward (see A. Munar’s talk)

29. T. Nelson, DIS 2003 - Slide 29 Angular Distributions: Interference p p  e+e+ e-e- Forward Backward + + + 2 1+ cos 2  cos  ? ? central-central + central-forward

30. T. Nelson, DIS 2003 - Slide 30 Forward di-electrons Selections : Electrons (forward only) – Isolated EM Calorimeter cluster – E T > 15 GeV – Calorimeter-seeded track Sample : ( 60 pb -1 Run 2 data) 843 events QCD background ( M ee > 100 GeV): w/o tracking: 60  5 stat % with tracking:4  3 stat % Similar to central-central background

31. T. Nelson, DIS 2003 - Slide 31 Outlook Goal: 200-320 pb -1 delivered in FY03 Store Number Total Luminosity ( pb -1 ) 100 200 150 Delivered To Tape CDF efficiency continues to improve, as well 2001 20022003

32. T. Nelson, DIS 2003 - Slide 32 Conclusions Preliminary results established for major electroweak benchmarks Broad top physics program is underway Promising searches in clean electroweak final states now match Run I sensitivity Improved detector, new techniques will extend reach beyond expected luminosity increases