From the Tevatron to the LHC Cosener’s House, April 24-25, 2004

1. From the Tevatron to the LHCCosener’s House, April 24-25, 2004 Morning Prayer John Ellis

2. Open Questions beyond the Standard Model • What is the origin of particle masses? due to a Higgs boson? + other physics? solution at energy < 1 TeV (1000 GeV) • Why so many types of matter particles? matter-antimatter difference? • Unification of the fundamental forces? at very high energy ~ 1016 GeV? probe directly via neutrino physics, indirectly via masses, couplings • Quantum theory of gravity? extra space-time dimensions? All these issues tackled by the LHC (Tevatron)

3. Electroweak Symmetry Breaking

4. The Electroweak Vacuum • Generating particle masses requires breaking gauge symmetry: mW,Z=/= 0 <0|XI|0> =/= 0 mW2 = mZ2 cos2θW => I = ½ • I = ½also needed for fermion masses • What is X? Elementary or Composite?

5. Higgs field: <0|H|0> =/= 0 Problems with loops Fermion-antifermion condensate Just like QCD, BCS superconductivity Top-antitop condensate? needed mt > 200 GeV Elementary Higgs or Composite? Cutoff Λ = 10 TeV • New technicolour force? • inconsistent with • precision electroweak data? • Cut-off Λ ~ 1 TeV with • Supersymmetry?

6. Indirect: Precision electroweak measurements at LEP, SLC, etc Predicted successfully mt = 160 – 180 GeV Sensitive to mass of Higgs boson mH < 200 GeV? Direct: LEP Searches for e+ e- -> Z + H Hint seen in late 2000 now < 2 σ Current Limit: mH > 114.4 GeV Searches for the Higgs Boson

7. mH > 114.4 GeV Waiting for the Higgs boson Higgs probability distribution: combining direct, indirect information How soon will the Higgs be found? …

8. Theorists getting Cold Feet • Interpretation of EW data? consistency of measurements?Discard some? • Higgs + higher-dimensional operators? corridors to higher Higgs masses? • Little Higgs models extra `Top’, gauge bosons, `Higgses’ • Higgsless models strong WW scattering, extra D?

9. What attitude towards LEP, NuTeV? Heretical Interpretation of EW Data Do all the data tell the same story? e.g., AL vs AH What most of us think

10. But conspiracies are possible: mH could be large, even if believe EW data …? Higgs + Higher-Order Operators Corridor to heavy Higgs? Precision EW data suggest they are small: why? Do not discard possibility of heavy Higgs

11. Little Higgs Models • Embed SM in larger gauge group • Higgs as pseudo-Goldstone boson • Cancel top loop with new heavy T quark • New gauge bosons, Higgses • Higgs light, other new physics heavy MT < 2 TeV (mh / 200 GeV)2 MW’ < 6 TeV (mh / 200 GeV)2 MH++ < 10 TeV Not as complete as susy: more physics > 10 TeV

12. Generic LittleHiggs Spectrum Loop cancellation mechanisms Supersymmetry Little Higgs

13. Higgsless Models • Four-dimensional versions: Strong WW scattering @ TeV, incompatible with precision data? • Break EW symmetry by boundary conditions in extra dimension: delaystrong WW scattering to ~ 10 TeV? Kaluza-Klein modes: mKK > 300 GeV? compatibility with precision data? • Warped extra dimension + brane kinetic terms? Lightest KK mode @ 300 GeV, strong WW @ 6-7 TeV

14. Tevatron & LHC

15. Updated Estimate of Tevatron Higgs Reach (June 2003)

16. Updated Tevatron Luminosity Projections

17. Proton- Proton Collider 7 TeV + 7 TeV Luminosity = 1034cm-2sec-1 The Large Hadron Collider (LHC) • Primary targets: • Origin of mass • Nature of Dark Matter • Primordial Plasma • Matter vs Antimatter

18. LHC Progress `Dashboard’

19. g – 2 of muon The First Direct Exploration of the TeV Scale … • Why is this interesting? Any new energy range takes us deeper inside matter, but also … • Several reasons to expect new physics: Origin of particle masses Stabilization of gauge hierarchy Unification of couplings Dark matter

20. The Physics Scope of the LHC Bread-and-butter physics Interesting cross sections W Δm = 15 MeV top Susy Δm = 1 GeV Higgs

21. … not far away? Combining direct, Indirect information A la recherche du Higgs perdu … Higgs Production at the LHC

22. Some Sample Higgs Signals ZZ* -> llll γγ ttH bbH

23. Measuring Higgs Self-Coupling Light Higgs @ low-energy LC Heavier Higgs possible @ SLHC LHC-LC report

24. Sensitivity to Strong WW scattering @ LHC @ 800 GeV LC LHC-LC report

25. Measuring WW Resonance Form factor measurements @ 500 GeV LC Resonance parameters @ LHC LHC-LC report Resonance parameters @ 500 GeV LC

26. Constraining Triple-Gauge Coupling

27. Other Physics @ EW Scale

28. Why Supersymmetry (Susy)? • Hierarchy problem:why is mW << mP ? (mP ~ 1019 GeV is scale of gravity) • Alternatively, why is GF = 1/ mW2 >> GN = 1/mP2 ? • Or, why is VCoulomb >> VNewton ? e2 >> G m2 = m2 / mP2 • Set by hand? What about loop corrections? δmH,W2 = O(α/π) Λ2 • Cancel boson loops  fermions • Need | mB2 – mF2| < 1 TeV2

29. It stabilizes the Higgs potential for low masses Other Reasons to like Susy It enables the gauge couplings to unify Approved by Fabiola Gianotti

30. gμ - 2 Constraints on Supersymmetry • Absence of sparticles at LEP, Tevatron selectron, chargino > 100 GeV squarks, gluino > 250 GeV • Indirect constraints Higgs > 114 GeV, b -> s γ • Density of dark matter lightest sparticle χ: WMAP: 0.094 < Ωχh2 < 0.124

31. Focus-point region above 7 TeV for mt = 178 GeV Current Constraints on CMSSM Excluded because stau LSP Excluded by b  s gamma WMAP constraint on relic density Excluded (?) by latest g - 2 Latest CDF/D0 top mass JE, Olive, Santoso, Spanos

32. Current Constraints on CMSSM Different tan β sign of μ Impact of Higgs constraint reduced if larger mt Focus-point region far up JE, Olive, Santoso, Spanos

33. Different Gravitino masses DifferentRegions of SparticleParameterSpace ifGravitino LSP Density below WMAP limit Decays do not affect BBN/CMB agreement JE, Olive, Santoso, Spanos

34. 500 (1000) GeV LC covers part of space

35. Supersymmetry Searches at LHC LHC reach in supersymmetric parameter space `Typical’ supersymmetric Event at the LHC

36. Observability of Lightest CMSSM Higgs Boson Cross section comparable to SM Higgs JE, Heinemeyer, Olive, Weiglein

37. Heavier MSSM Higgs Bosons Observability @ LHC LHC-LC report

38. CP Violation in the MSSM? • Assuming universality for the soft susy-breaking parameters • Two possible sources: Phase in trilinear term A:φA Phase in gluino mass:φ3 • Loop effects on MSSM Higgs bosons • CP-violating mixing: h, H A

39. Observability @ LEP & LHC Some uncovered regions of parameter space Assuming common value of φA, φ3 Carena, JE, Mrenna, Pilaftsis, Wagner

40. Cross Sections across Mixed Higgs Peaks φA = 90, φ3 = -90, -10 Diagrams Kinematics JE, Lee, Pilaftsis

41. CP-Violating Asymmetries Rather small Could be large! JE, Lee, Pilaftsis

42. Examples of Integrated Asymmetries Could be large! JE, Lee, Pilaftsis

43. Supersymmetric Benchmark Studies Lines in susy space allowed by accelerators, WMAP data Specific benchmark Points along WMAP lines Sparticle Detectability @ LHC along one WMAP line LHC enables calculation of relic density at a benchmark point Battaglia, De Roeck, JE, Gianotti, Olive, Pape

44. LHC and LCScapabilities LHC almost `guaranteed’ to discover supersymmetry if it is relevant to the mass problem LC oberves complementary sparticles Battaglia, De Roeck, JE, Gianotti, Olive, Pape

45. Example of Benchmark Point Spectrum of Benchmark SPS1a ~ Point B of Battaglia et al Several sparticles at 500 GeV LC, more at 1000 GeV, some need higher E LHC-LC report

46. Examples of Sparticle Measurements Threshold excitation @ LC Spectrum edges @ LHC Spectra @ LC LHC-LC report

47. Fit to CMSSM parameters Mass Measurements @ Benchmark B = SPS1a LHC-LC report

48. Supersymmetric Benchmark Studies Lines in susy space allowed by accelerators, WMAP data Specific benchmark Points along WMAP lines Sparticle detectability Along one WMAP line Calculation of relic density at a benchmark point Battaglia, De Roeck, JE, Gianotti, Olive, Pape

49. How `Likely’ are Large Sparticle Masses? Fine-tuning of EW scale Fine-tuning of relic density Larger masses require more fine-tuning: but how much is too much? JE, Olive, Santoso

50. If not supersymmetry, what ? Extra Dimensions ? - Suggested by Kaluza and Klein to unify gravity and electromagnetism - Required for consistency of string theory - Could help unify strong, weak and electromagnetic forces with gravity if >> lP - Could be origin of supersymmetry breaking - Enable reformulation of the hierarchy problem Reformulated