1. On the Brink of Revelation and Revolution: Electroweak Symmetry Breaking in 2008 Rick St. Denis – Glasgow University

2. Outline ● Higgs Decay Modes at Tev and LHC ● The two paths ● The CDF sensitivity ● Scenario ● HWW, Vector Boson Fusion Production of Higgs at TeV and LHC ● Conclusions

3. Higgs Production ● 4 main mechanisms ● Gluon Fusion Dominates at Tevatron: HWW ● Associated Production: WH, ZH, WWH, TTH  WW WH,ZH, WWH VBF TTH 

4. Higgs DIY (DYI?)

5. Kraemer vs. Pythia(6.2.2.2)

6. Production:Check Pythia, Kraemer, Spira Below 1

7. ZH corrections

8. Interesting Diversion: pp vs. ppbar  WW gg VBF

9. VBF 25% Better in PbarP u d W+W+ d d u W-W- d u W+W+ u W-W- pp: u d ppbar: u,d Hence: U U D 5 chances 4 chances Ratio is 5/4 = 1.25

10. Check of Higgs Branching Ratios B WW ZZ

11. Check of Higgs BR: Pythia/Spira 20-25% differences

12. CDF Channels NOW Ntupled 1fb -1 Total WH(l bb) WH-WWW VBF gg-WW ZH(llbb) ZH( bb) Used WW correction For VBF Before Selection! (  2-7%)

13. CDF (2009?) For 8fb -1

14. CDF Limits: (WW:360 pb -1 ) X 12 Jet Resolution

15. ATLAS Channels M H (GeV) 55 Deliberately Ignore  Should we invest in this? W,Z we know!

16. The Two Paths ● H to WW depends on jets, leptons (VBF too). Same at LHC, CDF. Have studied VBF and fascinating match of detectors to machines! ● ttH depends on jets, b-jets: tagging and mass resolution. WH,ZH depends on same: Huge synergy. Very different path. ● There are two natural divisions of effort: those that need silicon and those that don’t.

17. HWW/VBF Production Features ● Missing Et ● High Pt Leptons ● 2 forward jets, opposite in rapidity, high mass ● Spin 0 Higgs correlates spins of leptons: e,  parallel and neutrinos also ● VBF:  e-jet about 1-1.5 q q' q W+W+ W-W- H0H0 W+W+ W-W- e-e- e-e- ++ e  VBF same as WW, but with forward jets. Do analyses together. Very unique events.

18. Studies ● Backgrounds: top, fakes, WW ● WW *is* the right laboratory in any case, even if no Higgs. Something has to keep the cross section under control ● Need to get detector understood using Z’s to get e,  W’s for Missing Energy ● Need to understand top, WW for backgrounds ● Do the Higgs detection at the same time

19. Tevatron Projections 2007 2009

21. Virtual Measurement MtMt MwMw M h =91 +45 -32 GeV 68%CL M h <186 GeVM h <219 GeV if LEP 219 GeV 95% CL

22. Projections on Virtual

23. Higgs Mass Error: (Currently +45 –32= +49-35%) 95% CL at 60-90 GeV above M H Fit

24. The Tevatron picture is changing rapidly!

27. July 2005

28. Oct 2005

29. Improvements in Analysis: WW Acceptance E t l >10,20 GeV E t l >20,20 GeV

30. Improvements to Analysis: Associated Production Channels

31. Tevatron Lumi

34. Integrated Lumi Projections

35. Instantaneous Lumi Needed Current Peak Luminosity

36. To get the 2008 Picture, Need LHC Projections

37. Objectives for the Pilot RUN Reach a Luminosity of 10 32 Low Luminosity run at 25 ns separation Difficult to speculate further on what the performance might be in the first year. As always, CERN accelerators departments will do their best ! Lyn Evans Rolandi: LP20052007 2010 2009 2008 2011 1 10 30 Pilot: 300pb -1

38. 14 vs 1.860 TeV ● 1fb -1 LHC >= 8fb-1 Tevatron (Table from Fabioa Gionatti, LP2005)

39. ATLAS Channels M H (GeV) 55 Exclude/Evidence for from CDF (if b jet resolution) Exclude/ deviation Mtop, Mw

40. Scenario ● ATLAS 2007: Pilot Run, Z,W calib? 200pb -1 ● ATLAS 2008: Physics, 1fb -1 ● CDF 2007: 4fb -1 : HWW 4x3: at SM limit in the 140-170 range. TOP and W Mass improved as well, so SM fit limits narrower. ● Deviations building from expected limit: we focus on this range for ATLAS 2008. Perhaps SM fit narrowing on this range. ● Higgs is 130-150 OR 170-185. Perhaps SM Fit excludes upper range. ● CDF 2009: 3  at 120: ATLAS 2011? For discovery. CDF Keeps running!? ● ATLAS 2010: 10fb -1 : Discover it for > 130.

41. Look at HWW

42. HWW/VBF Production Features ● Missing Et ● High Pt Leptons ● 2 forward jets, opposite in rapidity, high mass ● Spin 0 Higgs correlates spins of leptons: e,  parallel and neutrinos also ● VBF:  e-jet about 1-1.5 q q' q W+W+ W-W- H0H0 W+W+ W-W- e-e- e-e- ++ e  VBF same as WW, but with forward jets. Do analyses together. Very unique events.

43. ● W + W - ● Drell-Yan: Z/  ● W + Jets (jet fakes e,  ) ● W+  HWW/VBF Backgrounds ● W Decay: 33% e,  ● Dilepton: 5%

44. Acceptance(m H = 160 GeV) CutEfficiency % 2 leptons (20, 10 GeV) 9.14±0.04 M ll > 16 GeV 96.1±0.06 Jet Veto 88.2±0.11 E T miss >m H /4 80.5±0.14 E T miss > 50 GeV or ∆  T 1/j  >20 o 96.4±0.07 Opposite Sign 98.7±0.04 M ll (1/2 x m H - 5) GeV 98.9±0.07 P T 1 + P T 2 + E T miss < m H 97.2±0.07 Jet |  |  < 2.5, 0-Jet or 15 < E T Jet1 < 55 GeV or 15 < E T Jet2 < 40 GeV Muons |  | < 1.0, Electrons |  | < 2.0

45. Acceptance

46. Background and Signal M H = 160 WW9.8±1.0 WZ0.37±0.05 ZZ0.04±0.01 tt0.35±0.04 WW 1.1±0.1 Drell-Yan0.76±0.19 fakes1.3±0.7 Total BG13±1.2 HWW0.58±0.04 Data16

47. Results

48. Study Characteristics at Tev and LHC for 160 s ^ q q' q W+W+ W-W- H0H0 W+W+ W-W- e-e- e-e- ++ e 

49. Tev,  H =160 Pt, Rapidity of Leptons, Jets Quark Forward Pt Quark can be low Electron In CDF Reasonably Triggerable

50. Pt, Rapidity of Leptons, Jets Quark more Forward Pt Quark can be low Electron In CDF: wider distn At LHC Reasonably Triggerable LHC,  H =160

51. Rapidity of two quarks Min  of 2 quarks Max  of 2 quarks  of 2 quarks Tev,  H =160

52. Rapidity of two quarks Min  – wider Max  of 2 Quarks wider  of 2 Quarks wider LHC,  H =160

53. Missing Energy Tev,  H =160 60 GeV Met Met vs Pte Quark can be along Met Met 180 o from e

54. Missing Energy A bit larger at LHC LHC,  H =160

55. Lepton Correlations:e- e Tev,  H =160 e, e anticorrelated in   (e, e )

56. Lepton Correlations:e- e LHC,  H =160 e, e anticorrelated less sharply in   (e, e )

57. Lepton Correlations: e-  e,  correlated in y,phi and have high p t Tev,  H =160 RR

58. Lepton Correlations e,  better correlated LHC,  H =160

59. Masses High Invariant Mass between quarks Large Invariant Mass between leptons Mt for e  Tev,  H =160

60. Masses Higher Invariant Mass between quarks Larger Invariant Mass between leptons Mt for e  LHC,  H =160

61. Electron-Jet Separation Tev,  H =160

62. Electron-Jet Separation LHC,  H =160 Same l-j separation

63. Summary/Conclusions ● CDF/ATLAS interest in W decay modes. ● Detector expertise/studies in Z,W to leptons: Where our efforts should be. ● Some jets interest, but not absolutely needed. ● WW is the right laboratory for studying EW Sym Breaking. ● Tevatron will have clear statements from Direct and Indirect searches when LHC searchs get serious.

64. Backup

65. HWW

66. Z( )H(bb)

67. Selection

68. Acceptance

69. Background No Lepton Lepton>=1  Lepton-jet)

70. Control Region 2

71. Control Region 1

72. Result (Signal Region)

73. W  l  H(bb)

74. Selection ● High Pt Lepton ● Missing Energy ● Displaced Vertex

75. Acceptance

76. Background(>=1 tag) W + Jets

77. Background(2 tags)

78. Result(Njet)

79. Result(no btag)

80. Result (>=1 btag)

81. Njet (>=2 btag)

82. Result >=2 btag

83. Z(ll)H(bb) No RunII Results Yet

87. ttH (No Run II result)

89. Background

90. Acceptance

91. Mt, Mw projections

92. M top Projection

93. Mw Projection

94. Background and Signal