1. Physics results with W/Z from Tevatron Marco Rescigno INFN/Roma On behalf of CDF and D0 collab. Moriond EWK, 6-13 2010 Topics W mass and width W asymmetry and Z/  * differential x-section Z/W + jet Z/W + Heavy Flavor jets

2. M.Rescigno - Moriond EWK 2010 2 Introduction & Outline Precision Physics  M w   W  Impact on EWK global fits W/Z prod. properties as a probe for PDF  W charge asymmetry  Z boson rapidity QCD test in high Q 2 multi-parton final states  W + jets  Z + jets

3. M.Rescigno - Moriond EWK 2010 3 MWMW High precision measurement from Tevatron (0.05%) requires precision lepton momentum and recoil momentum calibration (driven by the Z  ll statistics) World best result from D0 [ Phys. Rev. Lett. 103, 141801 (2009 )]  See YSF1 S.Yacoob this afternoon Tevatron average more precise than LEP direct measurement! 0.2 fb -1 1.0 fb -1

4. M.Rescigno - Moriond EWK 2010 4 MWMW M W vs M top + EWK precision observables favor low mass SM Higgs M top + EWK fits predict M W mass to 20 MeV/c 2 M W measured to ~10 MeV/c 2 highly desirable, could hint to New Physics CDF (2 fb -1 ) expects ~ 15 MeV/c 2 stat uncertainty per channel Controlling syst. at that level requires control of higher order QED radiation and PDF  theory connection

5. M.Rescigno - Moriond EWK 2010 5 *  W = 2.033 ± 0.072 GeV/c 2 PRL. 103, 231802 (2009)  W = 2.034 ± 0.072 GeV/c 2 PRL 100, 071801(2008)  W results Fit to the high-end tail of the transverse mass peak CDF/D0 both surpassed in Run II average LEP2 direct measurements SM prediction by far more precise * Tevatron average do not include yet new D0 result. The soon to be released one will improve by 10 MeV

6. M.Rescigno - Moriond EWK 2010 6 Rare W Decay Clean final state : enhanced by anomalous  -W couplings. SM branching fraction : 10 -6 - 10 -8 Becomes sensitive to new physics with data samples of several million W W-W-   W-W- 206 candidate events in signal (75 < M πγ < 85 GeV) region NEW

7. M.Rescigno - Moriond EWK 2010 7 W asymmetry Phys. Rev. Lett. 101, 211801 (2008) 0.70 fb -1 (electron) D0 note E31 4.9 fb -1 (muons) Phys. Rev. Lett. 102, 181801 (2009) 1.0 fb -1 (electron) In p-pbar collisions W + tend to go in p direction: u quark carries more momentum than d on average For lepton asymmetry consider also V-A decay: e + in pbar direction (for W + production off valence quarks) W ± charge asymmetry sensitive probe of the fractional momentum difference b/w u and d quarks NEWNEW

8. M.Rescigno - Moriond EWK 2010 8 W asymmetry Compared to CTEQ 6.1/6.6 and MRST PDF sets. Good agreement and total experimental uncertainty significantly smaller than PDF uncertainty band

9. M.Rescigno - Moriond EWK 2010 9 W asymmetry Compare D0 and CDF measurements in 2 lepton p T bins and with CTEQ 6.6 Experiments ~agree Effort ongoing to understand discrepancy with current PDF at high p T

10. M.Rescigno - Moriond EWK 2010 10 CDF 2.1 fb -1 (electron) arXiv:0908.3914 σ = 256.6 ± 0.7(stat.) ± 2.0 (syst.) pb d  /dy(Z/   e + e - ) Probe low-x PDF through high rapidity Drell-Yan pairs Compare with CTEQ and MRST/MSTW2008 Good agreement within quoted uncertainty CDF Run II preliminary

11. M.Rescigno - Moriond EWK 2010 11 Vector Bosons + jets W/Z used as a clean probe of high Q^2 processes with multi-parton final states High statistic available at the Tevatron allow detailed comparisons with:  NLO calculations available up to 3 jets for certain processes  Matched Tree Level Matrix-Element + parton shower MC (Alpgen, Sherpa) Valuable tools for “discovery” physics that need to be validated Crucial backgrounds for top physics and Tevatron Higgs searches CDF W(e )+jet Phys. Rev. D77, 011108 (2008). CDF Z(ee)+jet Phys. Rev. Lett. 100, 102001 (2008) CDF Z(  )+jet CDF QCD web page CDF Z(e+  )+ b-jet Phys. Rev. D79, 052008 (2009) CDF W(e+  )+b-jet arXiv: 0909.1505. Sub. to Phys. Rev. Lett D0 Z(  )+jet Phys. Lett. B 682, 370 (2010) D0 Z(ee)+jet Phys. Lett. B 678, 45 (2009)

12. M.Rescigno - Moriond EWK 2010 12 Page 12 W + Inclusive Jets CDF W+jets analysis: 320/pbCDF W+jets analysis: 320/pb W(  e ) selection:W(  e ) selection:  e: E T > 20 GeV, |  | 20 GeV, |  | < 1.1  : missing energy > 30 GeV  M T (W) > 20 GeV/c 2 Jet definition:Jet definition:  Corrected E T > 20, |  | 20, |  | < 2.0  JetClu w/ cone R= 0.4   R(e, jet) > 0.52 Major backgrounds:Major backgrounds:  leptonic (W , Z  ee, WW, W , tt  multijet (Fake W signature + jets) CDF collab. PRD 77, 011108(R) NLO prediction ~ OK (existed up to 2 jet) MLM : ALPGEN v2.12 (LO) + Herwig v6.5 + MLM + CTEQ5L SMPR: MadGraph v4 (LO) + Pythia v6.3 + CKKW + CTEQ6L1 MCFM: NLO, no showering + CTEQ6.1M

13. M.Rescigno - Moriond EWK 2010 13 Page 13 W + Inclusive Jets E T Spectra Difficult to simulate. Simplification strategies:Difficult to simulate. Simplification strategies:  Generate 2  2 and use parton shower  Generate 2  N processes but ignore virtual corrections (loops) Neither alone is ideal, so hybrid scheme of the two is employedNeither alone is ideal, so hybrid scheme of the two is employed Ambiguities ariseAmbiguities arise  Possibility for double counting  “SMPR” and “MLM” refer to algorithms for removing overlaps SMPR (CKKW): S.Mrenna, P.Richardson JHEP, 05(2004) 040SMPR (CKKW): S.Mrenna, P.Richardson JHEP, 05(2004) 040 MLM: J.Alwall et al. arXiv:0706.2569MLM: J.Alwall et al. arXiv:0706.2569 W+n-jet cross section better reproduced by SMPR treatment:W+n-jet cross section better reproduced by SMPR treatment:  overlap removal or tuned UE in Pythia? 3 rd jet 2 nd jet 1 st jet

14. M.Rescigno - Moriond EWK 2010 14 W+3 jet @ NLO Last year calculations @NLO appeared that can be compared to CDF data also for 3 jet events R.K.Ellis,Melnikov,Zanderighi arXiv:0906.1405 C.F. Berger et al., arXiv:0907.1984

15. M.Rescigno - Moriond EWK 2010 15 Page 15 Z/  * + Inclusive Jets CDF Z /  *+jets analysis: 1.7/fb (electron) 2.4 /fb (muons)CDF Z /  *+jets analysis: 1.7/fb (electron) 2.4 /fb (muons) Z /  * selection: seek Z /  *  e + e - (     )Z /  * selection: seek Z /  *  e + e - (     )  Two E T (p T )> 25 GeV leptons  66 < M ℓ ℓ < 116 GeV/c 2  At least one e w/ |  | < 1.1, else 1.2 < |  | < 2.8  For muons |  |<1.0 Jet definition:Jet definition:  Corrected p T > 30, |y| 30, |y| < 2.1  MidPoint w/ R=0.7   R(e, jet) > 0.7 Major backgrounds: S/B ~ 7/1Major backgrounds: S/B ~ 7/1  Multijet  W+jets CDF collab. PRL 100, 102001 (2008) hep-ex/0711.3717

16. M.Rescigno - Moriond EWK 2010 16 Page 16 Z/  * + Inclusive Jets CDF Z /  *+jets analysis: 1.7/fb (electron) 2.4 /fb (muons)CDF Z /  *+jets analysis: 1.7/fb (electron) 2.4 /fb (muons) Z /  * selection: seek Z /  *  e + e - (     )Z /  * selection: seek Z /  *  e + e - (     )  Two E T (p T )> 25 GeV leptons  66 < M ℓ ℓ < 116 GeV/c 2  At least one e w/ |  | < 1.1, else 1.2 < |  | < 2.8  For muons |  |<1.0 Jet definition:Jet definition:  Corrected p T > 30, |y| 30, |y| < 2.1  MidPoint w/ R=0.7   R(e, jet) > 0.7 Major backgrounds: S/B ~ 7/1Major backgrounds: S/B ~ 7/1  Multijet  W+jets CDF collab. http://www- cdf.fnal.gov/physics/new/qcd/Zjets_mum u2010/index.html NEW

17. M.Rescigno - Moriond EWK 2010 17 Page 17 Z /  * + Inclusive Jets D0 measure 1 st, 2 nd,3 rd jet p T spectraD0 measure 1 st, 2 nd,3 rd jet p T spectra Compare to MCFM pQCD NLO and generatorsCompare to MCFM pQCD NLO and generators D0 collab. Phys. Lett. B 678, 45 (2009), arXiv.org:0903.1748 Z+2jet Z+3jet

18. M.Rescigno - Moriond EWK 2010 18 W + b-Jets CDF W+b-jets analysis: 1.9/fbCDF W+b-jets analysis: 1.9/fb Goals:Goals:  Measure jet cross section  Compare to theory  Use measurement in background estimate for Higgs search W selection:W selection:  p T > 20 isolated central e or   Missing energy MET > 25 GeV Jet selection:Jet selection:  1 or 2 corrected E T >20 GeV, |  | < 2.0 JetClu R=0.4 jets  High purity secondary vertex tag Page 18 Extract species content via vertex mass, M vert : CDF collab. arXiv:0909.1505v2 (Submitted to PRL)arXiv:0909.1505v2 NEW

19. M.Rescigno - Moriond EWK 2010 19 Largest backgrounds: S/B ~ 3/1Largest backgrounds: S/B ~ 3/1  ttbar (40% of total bkgd)  single top (30%)  Fake W (15%)  WZ (5%) Result:Result:  x BR = 2.74  0.27 (stat)  0.42 (syst) pb Predictions:Predictions:  x BR = 0.78 pb  x BR = 0.78 pb ALPGEN v2.10’ + Pythia v6.325 + MLM + CTEQ6L (  =M W 2 +p TW 2 )  x BR = 1.1 pb (Pythia)  x BR = 1.1 pb (Pythia)  x BR = 1.22 ±0.14 pb (NLO – Campbell, Freres-Cordero, Reina)  x BR = 1.22 ±0.14 pb (NLO – Campbell, Freres-Cordero, Reina) W + b-Jets Page 19 This cross section is for b jets from W+b-jet production in events with a high p T central lepton, high p T neutrino and 1 or 2 total jets. Shape comparisons? NLO comparison? mismatch by a factor 2  3.5 (~2.9  ) Differential measurement with increased statistics underway

20. M.Rescigno - Moriond EWK 2010 20 Page 20 Z + b-Jets Similar CDF analysis for Z+b-jets: 2/fbSimilar CDF analysis for Z+b-jets: 2/fb Utilize Z  ee, Utilize Z  ee,  Jet definition:Jet definition:  Corrected E T > 20 GeV, |  | 20 GeV, |  | < 1.5  JetClu R=0.7 Differential cross sections with comparisons to LO, NLO predictions Differential cross sections with comparisons to LO, NLO predictions Pythia ~ OK at low jet ET Pythia ~ OK at low jet ET ALPGEN and MCFM undershoot data in several bins  tuning  R improves agreement ALPGEN and MCFM undershoot data in several bins  tuning  R improves agreement CDF collab. PRD 77, 011108(R)

21. M.Rescigno - Moriond EWK 2010 21 Conclusions CDF and D0 reached unprecedented precision on W mass and width  Legacy measurements that will be further improved and could challenge the SM W/Z clean probes for proton PDF  W asymmetry at high lepton E T still an issue With multi-fb -1 data set detailed comparison of multi-jet events in association with W/Z  NLO pQCD in good shape (exception W+bjet?)  Matrix-Element + parton shower MC do a fairly good job in describing spectra but can be further tuned

22. BACKUP

23. M.Rescigno - Moriond EWK 2010 23

24. M.Rescigno - Moriond EWK 2010 24 M W syst.

25. M.Rescigno - Moriond EWK 2010 25 CDF 2.1 fb -1 (electron) arXiv:0908.3914 σ = 256.6 ± 0.7(stat.) ± 2.0 (syst.) pb d  /dy(Z/   ll) Probe low-x PDF through high rapidity Drell-Yan pairs

26. M.Rescigno - Moriond EWK 2010 26 Page 26 W + Inclusive Jets Spectra OK up to 4 parton in the final state, normalization in these plots “ad- hoc” (scaled to the first bin).Spectra OK up to 4 parton in the final state, normalization in these plots “ad- hoc” (scaled to the first bin).

27. M.Rescigno - Moriond EWK 2010 27 Page 27 Z /  * + Inclusive Jets NLO predictions for jet p T differential cross section are accurateNLO predictions for jet p T differential cross section are accurate NLO predictions for jet multiplicity also accurateNLO predictions for jet multiplicity also accurate  NLO-to-LO scaling appears to be a safe thing to do here

28. M.Rescigno - Moriond EWK 2010 28 Page 28 Z + b-Jets V+b-Jets Summary:

29. M.Rescigno - Moriond EWK 2010 29 PDF with Tevatron data

30. M.Rescigno - Moriond EWK 2010 30 Rare W Decays W-W-   W-W- Clean final state : enhanced by BSM physics. SM branching fraction : 10 -6 - 10 -8 Becomes sensitive to new physics with data samples of several million Ws

31. M.Rescigno - Moriond EWK 2010 31 Rare W Decays 206 candidate events in signal (75 < M πγ < 85 GeV) region Predicted background = 219