1. Tevatron Electroweak Results And Electroweak Summary Sean Mattingly Brown University For the CDF and DZero Collaborations XXIV Physics in Collision Boston, MA 29 June 2004

2. Sean Mattingly XXIV PiC 29 June 2004 2 W and Z production Well understood event signatures –Leptonic decay modes avoid high jets backgrounds –Increase understanding of detector by studying W/Z production Cross sections are relatively well known and high –High statistics and clean event signatures  precision measurements such as… p p q’ q W±W± e,  p p q q Z0/Z0/ e +,  + e -,  - BR = ~10%BR = ~3% Electroweak Physics at the Tevatron

3. Sean Mattingly XXIV PiC 29 June 2004 3 Tevatron Electroweak Measurements W production –Decays to e, ,   lepton universality –Charge asymmetry  constrain PDFs –Transverse mass distribution  direct W mass & width –Constrain Higgs mass Z production –Search for Z’ resonances –Forward-backward asymmetry  sin 2 (  w ), quark couplings Combined W/Z –Ratio of W/Z cross sections * BR  indirect W width Diboson production - WW/WZ/W  /Z  –Triple & quartic gauge couplings W/Z/Diboson production are important backgrounds for top, Higgs and SUSY production

4. Sean Mattingly XXIV PiC 29 June 2004 4 W/Z Event Signatures W production  Can’t measure p Z of (LEP/TeV) Z production e+,+e+,+ q e-,-e-,- Hadronic Recoil q q’ e,  Hadronic Recoil q (LEP)

5. Sean Mattingly XXIV PiC 29 June 2004 5 Detectors  = -1  = -2 Run II Luminosity Typically: ~6 x 10 31 / cm 2 s Record: 8.5 x 10 31 / cm 2 s Delivered: ~570 pb -1 Recorded: ~400 pb-1 / expt ~100K Zs, ~10M Ws /lept chan Goal: 4.4 fb -1 by end FY 09 DZero Run II upgrades 2T solenoid, inner tracking Preshower  system/shielding Trigger, DAQ CDF Run II upgrades Inner tracking Forward calorimeter Extended  system Trigger, DAQ CDF Analyses: 65-200 pb -1 DZero Analyses: 42-162 pb -1

6. Sean Mattingly XXIV PiC 29 June 2004 6 Analysis Methods Triggers –Electrons: EM calorimeter –Muons: track + muon system Electron ID –High E T isolated EM calorimeter cluster usually w/ track match Muon ID –High E T isolated track matched to muon detector track or calorimeter MIP Z candidates –2 leptons w/ invariant mass consistent with Z mass W candidates –1 lepton & missing E T > 25 GeV ID efficiencies measured in Z events Primary backgrounds determined using data jet events

7. Sean Mattingly XXIV PiC 29 June 2004 7  *BR(Z  ee) Two electrons, E T > 25 GeV –DZero: |  | < 1.1, CDF: full detector (1 st EM central) Small backgrounds from jets, Z  ,(DY correction) DZero Run II Preliminary Bkg Bkg+MC Signal Data No track match L=42 pb -1

8. Sean Mattingly XXIV PiC 29 June 2004 8  *BR(Z   ) Two opposite charged muons, p T > 15-20 GeV –CDF: |  | < 1.0, DZero |  |< 1.8 Very small backgrounds : jets(b), Z  , cosmics, (DY corr.)

9. Sean Mattingly XXIV PiC 29 June 2004 9  *BR(W  e ) One electron, p T > 25 GeV, missing E T > 25 GeV –DZero: |  | < 1.1, CDF: central & plug Backgrounds: jets, W  , Z  ee Points: Background Subtracted Data Histogram: W  e MC L=42 pb -1

10. Sean Mattingly XXIV PiC 29 June 2004 10  *BR(W   ) One muon, p T > 20 GeV, missing E T > 20 GeV –DZero: |  | < 1.6 (from initial lumi), CDF: |  | < 1.0 Backgrounds: Z  , W   jets(b) L=17 pb -1

11. Sean Mattingly XXIV PiC 29 June 2004 11 CDF/DZero Comparison Similar efficiencies and purities –CDF: Includes forward electrons –DZero: Includes farther forward muons Channel# events Purity (%) Luminosity Used (pb -1 )  * A (%) W  e CDF 48.0K94.07223.1 DZero27.4K95.74118.4 W   CDF 31.7K90.07214.4 DZero8.3K88.01713.2 Z  ee CDF 424298.57222.7 DZero113998.3419.97 Z   CDF 178598.57210.2 DZero612698.911716.4

12. Sean Mattingly XXIV PiC 29 June 2004 12 W/Z Cross Sections Summary Van Neerven, Matsuura

13. Sean Mattingly XXIV PiC 29 June 2004 13 Indirect W Width CDF combined electron & muon channels Tree level NNLO QCD calc (Van Neerven) PDG(LEP) SM EWK Calculation

14. Sean Mattingly XXIV PiC 29 June 2004 14 Toward Higher Precision Luminosity error 10%  6.5% –CDF and DZero use same luminosity constants Added luminosity –Improved statistical errors –Smaller lepton ID systematics –Refined background estimates Improved detector simulation –Energy scale (EM and Hadronic), detector geometry and material description PDFs –Using CTEQ6 and MRST sets w/ error sets Combine CDF and DZero results –Tevatron Electroweak working group –Standardized error reporting –Account for error correlations –http://tevewwg.fnal.gov Use precision measurements in electroweak fits (see 2 nd part of talk)

15. Sean Mattingly XXIV PiC 29 June 2004 15 Physics with  Z    leptonic   (1 prong  hadronic  –Demonstrates visibility of  resonances at the Tevatron –DZero: muonic decays + observe N  0, CDF: electronic decays  Visible Mass (GeV) D0 Run II preliminary L=68 pb -1

16. Sean Mattingly XXIV PiC 29 June 2004 16 Physics with  (cont) W   CDF) –Trigger on track + missing E T –Count tracks in 10 o cone, veto on tracks in 30 o cone –Reconstruct  0 with detectors at shower max –Combined mass < M  –Backgrounds: W  , W  e, Z  , jets

17. Sean Mattingly XXIV PiC 29 June 2004 17 Forward-backward Asymmetry e−e− p e+e+ p  Z/  *  e + e - (CDF) –At Tevatron can measure at Z pole and above and below –Directly probes V-A, extract sin 2  W and u/d couplings to Z

18. Sean Mattingly XXIV PiC 29 June 2004 18 W Charge Asymmetry W  e (CDF) –Up-type quarks carry more average momentum –W + boosted in p direction, W - boosted in p direction –Charge asymmetry as function of rapidity constrains PDFs –Cannot unambiguously determine W ± ’s direction (lost ) but e ± direction carries W ± direction information –Measure charge asymmetry using e ± rapidity –Higher E T e ± more closely aligned with W ± direction –Main constraints for forward rapidities –Ratio of u/d PDFs

19. Sean Mattingly XXIV PiC 29 June 2004 19 W Charge Asymmetry (cont) Select W events and identify charge – 50 25 GeV – Use calorimeter seeded tracking with forward silicon to determine charge out to |  det | < 2 – Charge mis-ID rate measured using Z  ee – < 1% for |  det | < 1.5, < 4% farther forward – Backgrounds bias asymmetry toward zero – Z  ee, W   subtracted using MC, jets using data

20. Sean Mattingly XXIV PiC 29 June 2004 20 Drell-Yan Invariant Mass Spectrum CDF/DZero Compare to Drell-Yan –Set limits on Z’, extra dimensions, etc. –Improve on Run I limits, test new models Di-EM Mass (GeV) 95% CL, M(Z’/SM) > 780 GeV 95% CL, M(Z’/SM) > 735 GeV

21. Sean Mattingly XXIV PiC 29 June 2004 21 Diboson Production Tevatron collisions can produce W , Z , WW, WZ, ZZ –Probe the gauge structure of electroweak –Search for anomalous couplings –Improve diboson modeling –Diboson production backgrounds in searches for new physics Leptonic decay modes –Minimize jet backgrounds

22. Sean Mattingly XXIV PiC 29 June 2004 22 Diboson Production: W  W   (e/  : First  select W  l events (CDF/DZero) –Add photon requirement: isolated EM, no track, shower max –Photon E T > 7-8 GeV, lepton-photon  R > 0.7, |   | < 1.1 –Backgrounds: W+jet, Z+ , Z+jet, “leX”, W   Initial State Radiation Final State Radiation WW  : Triple Gauge Coupling D0 RunII preliminary W  (e/  )  L(e) = 162 pb -1 L(  ) = 82 pb -1

23. Sean Mattingly XXIV PiC 29 June 2004 23 Diboson Production: W  Cross Sections DZero (  E T > 8 GeV)CDF (  E T > 7 GeV) W   e  162 pb -1 W    82 pb -1 W   (e/  )  202 pb -1 W+jet80.0 ± 7.430.1 ± 10.049.52 ± 14.95 Z+  4.7 ± 2.022.37 ± 1.26 “leX”3.7 ± 0.50.6 ± 0.6 W    3.4 ± 1.10.9 ± 0.33.23 ± 0.29 Total Bkg87.1 ± 7.537 ± 1075.12 ± 15.01 Total SM142 ± 1767 ± 13255.63 ± 26.52 Data14677259  *BR(l  ) 19.3 ± 2.7(stat) ± 6.1(sys) ± 1.2 (lumi) pb19.7 ± 1.7(stat) ± 2.0(sys) ± 1.1(lumi) pb Baur NLO16.4 ± 0.4 pb19.3 ± 1.3 pb

24. Sean Mattingly XXIV PiC 29 June 2004 24 Initial State Radiation Final State RadiationZZg: Triple Gauge Coupling Diboson Production: Z  Z  (e/  )  (CDF) –Z selection + photon –Photon E T > 7 GeV,  R(l  ) > 0.7, |   | < 1.1 –Relative backgrounds smaller than for W  –Main background: Z+jet

25. Sean Mattingly XXIV PiC 29 June 2004 25 Diboson Production: Z  Cross Section CDF: Z   (ee/  )  202 pb -1 Total Bkg4.4 ± 1.3 Total SM70.5 ± 4.0 Data69  *BR(l  ) 5.3 ± 0.6(stat) ± 0.4(sys) ± 0.3(lumi) pb Baur NLO5.4 ± 0.4 pb

26. Sean Mattingly XXIV PiC 29 June 2004 26 Diboson Production: WW Two analyses from CDF –High purity: identify 2 leptons –High efficiency: identify 1 lepton + 1 isolated track –Backgrounds: DY, WZ/ZZ/W , Z  , tt  llX, fakes H  WW (CDF/DZero): See E. Nagy’s talk Purity analysis –2 high p T leptons –Opposite sign –Missing E T > 25 GeV –Veto if any high E T jets –Reject if dilepton mass near Z mass and (missing E T )/ (scalar summed E T ) < 3

27. Sean Mattingly XXIV PiC 29 June 2004 27 Diboson Production: WW (cont.) Efficiency analysis –1 high p T lepton + 1 isolated high p T track –Missing E T > 25 GeV –Veto if > 1 high E T jet –Reject (missing E T )/(scalar summed E T ) < 5.5 CDF: Purity AnalysisCDF: Efficiency Analysis WW 11.3 ± 1.3 16.3 ± 0.4 DY1.1 ± 0.41.8 ± 0.3 WZ+ZZ+W  1.8 ± 0.12.4 ± 0.1 Top0.05 ± 0.021.8 ± 0.1 Fakes1.1 ± 0.59.1 ± 0.8 Total Bkg4.8 ± 0.715.1 ± 0.9 Total SM16.1 ± 1.631.5 ± 1.0 Data1739  (WW) 14.2 ± 5.6 4.9 ± 1.6 ± 0.9 pb19.4 ± 5.1 ± 3.5 ± 1.2 pb NLO Ellis & Campbell: 12.5 ± 0.8 pb

28. Sean Mattingly XXIV PiC 29 June 2004 28 ZZ/WZ Final States Look for leptonic final states (CDF) –2-4 high p T leptons in e and  channels (194 pb -1 ) –ZZ  llll or ll and WZ  l ll –Require one lepton pair to be consistent with Z mass –5.1 ± 0.7 expected –4 observed –95% CL:  (ZZ/WZ) < 13.8 pb -1 –SM (Ellis & Campbell) = 5.2 pb

29. Sean Mattingly XXIV PiC 29 June 2004 29 Precision Electroweak Measurements And Electroweak Radiative Corrections Large number of measurements from LEP, SLC and Tevatron –W mass/width (Tevatron, LEP-2) –Top quark mass (Tevatron) –Z-pole measurements (LEP, SLD) –Z lineshape parameters –Polarized leptonic asymmetries –Heavy flavor asymmetries and branching fractions –Hadronic charge asymmetry In the SM, each observable can be calculated/fit in terms of –  had,  s (M Z ), M Z, M W, sin 2  W, M top, M higgs, etc… –Higgs & top enter as ~1% radiative corrections –LEP Electroweak Working Group –ZFITTER, TOPAZ0 } Recent and future updates

30. Sean Mattingly XXIV PiC 29 June 2004 30 W Mass/Width Tevatron W mass and width –From fits to M T spectrum LEP-2 W mass and width –From reconstructing Ws –e + e -  WW  qqqq or qql –Difference between two final states:  m W = 22 ± 43 MeV

31. Sean Mattingly XXIV PiC 29 June 2004 31 W Mass Prospects Final CDF/DZero Run I W mass 80.452 ± 0.059 GeV } Errors decrease with larger Run II luminosity and Run II detector upgrades } Run II measurements of W charge asymmetry and Z rapidity distribution constrain PDF  reduce PDF uncertainty Run II uncertainty goal 40 MeV per experiment –~25 MeV combined (TEVEWWG)

32. Sean Mattingly XXIV PiC 29 June 2004 32 Top Quark Mass DZero update on Run 1 result –M top = 180.1 ± 5.3 GeV –~15% smaller error than previous Preliminary CDF Run 2 results –See talk by A. Hocker –Not yet included in fits Expected Run 2 accuracy: 2.5 GeV

33. Sean Mattingly XXIV PiC 29 June 2004 33 W and Top Mass in Electroweak Fit Z-pole measurements –Use fit to indirectly predict W/top mass (LEP-1, SLD) –Direct and indirect agree –Test of SM –Both favor lighter Higgs (indirect) (direct) LEPEWWG

34. Sean Mattingly XXIV PiC 29 June 2004 34 Electroweak Fit: Top Mass Predicted and measured M top in good agreement –Measurement uncertainty half of prediction uncertainty LEPEWWG

35. Sean Mattingly XXIV PiC 29 June 2004 35 Electroweak Fit: W Mass Predicted and measured M W in agreement –Measured M W not yet as accurate as prediction –Combined CDF/DZero Run II W mass: expect ~similar accuracy to prediction LEPEWWG

36. Sean Mattingly XXIV PiC 29 June 2004 36 Electroweak Fit: Higgs Mass Fit using high Q 2 (LEP, SLC, Tevatron) data –Most likely M Higgs = 113 ± 62 42 GeV –M Higgs < 237 GeV (95% CL) LEPEWWG A. Quadt Year

37. Sean Mattingly XXIV PiC 29 June 2004 37 Electroweak Fit: Summary Fit to all observables –  2 /N dof = 16.3/13 –Largest pull from b A FB –2.5  effect in opposite direction of next largest pull: A l (SLD) –Accurately predicts low Q 2 measurements –Atomic parity violation –Moller scattering –NuTeV? LEPEWWG

38. Sean Mattingly XXIV PiC 29 June 2004 38 NuTeV’s Result Paschos-Wolfenstein relation: neutrinos on isoscalar target sin 2  W = 0.22773 ± 0.00135(stat) ± 0.00093(syst) [SM = 0.2226 ± 0.0004] Or…assuming sin 2  W is in agreement (i.e. M W /M Z ) –  = 0.988 ± 0.004 3  effect –New physics? New particles, oscillations, etc… –Old physics? PDFs, non-isoscalar target, sea asymmetry, etc…  q q W ± /Z

39. Sean Mattingly XXIV PiC 29 June 2004 39 Conclusion Many Tevatron Run II electroweak measurements –Detector understanding increasing –~200pb -1 of luminosity analyzed per experiment –Preliminary W mass measurements soon –TEVEWWG will combine CDF and DZero measurements Standard Model describes large number of measurements with precision –Discrepancies can be interpreted as statistical fluctuations –Higgs mass constrained < 237 GeV, most likely M Higgs = 113 ± 62 42 GeV –Upcoming Tevatron Run 2 top quark and W mass measurements important components in Higgs mass constraints