Search for Supersymmetry

1. Search for Supersymmetry

2. Outline • Introduction to supersymmetry • Phenomenology of the CMSSM • Non-universal scalar masses? • Non-universal Higgs masses (NUHM) • Options for the LSP • Gravitino dark matter • New possibilities for collider phenomenology

3. Loop Corrections to Higgs Mass2 • Consider generic fermion and boson loops: • Each is quadratically divergent: ∫Λd4k/k2 • Leading divergence cancelled if Supersymmetry! 2 ∙2

4. Other Reasons to like Susy It enables the gauge couplings to unify It predicts mH < 150 GeV As suggested by EW data JE, Nanopoulos, Olive + Santoso: hep-ph/0509331 Approved by Fabiola Gianotti

5. Astronomers say that most of the matter in the Universe is invisible Dark Matter Lightest Supersymmetric particles ? We shall look for them with the LHC

6. Minimal Supersymmetric Extension of Standard Model (MSSM) • Particles + spartners • 2 Higgs doublets, coupling μ, ratio of v.e.v.’s = tan β • Unknown supersymmetry-breaking parameters: Scalar massesm0, gaugino massesm1/2, trilinear soft couplingsAλ, bilinear soft couplingBμ • Often assume universality: Singlem0, singlem1/2, singleAλ,Bμ: not string? • Called constrained MSSM = CMSSM • Minimal supergravity (mSUGRA) predicts additional relations for gravitino mass, supersymmetry breaking: m3/2 = m0,Bμ = Aλ – m0

7. Lightest Supersymmetric Particle • Stable in many models because of conservation of R parity: R = (-1) 2S –L + 3B where S = spin, L = lepton #, B = baryon # • Particles have R = +1, sparticles R = -1: Sparticles produced in pairs Heavier sparticles  lighter sparticles • Lightest supersymmetric particle (LSP) stable

8. Possible Nature of LSP • No strong or electromagnetic interactions Otherwise would bind to matter Detectable as anomalous heavy nucleus • Possible weakly-interacting scandidates Sneutrino (Excluded by LEP, direct searches) Lightest neutralino χ Gravitino (nightmare for astrophysical detection)

9. 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

10. Current Constraints on CMSSM Assuming the lightest sparticle is a neutralino Excluded because stau LSP Excluded by b  s gamma WMAP constraint on relic density Excluded (?) by latest g - 2 JE + Olive + Santoso + Spanos

11. 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

12. Sparticles may not be very light Full Model samples ← Second lightest visible sparticle Detectable @ LHC Provide Dark Matter Dark Matter Detectable Directly Lightest visible sparticle → JE + Olive + Santoso + Spanos

13. Missing Energy Detection @ LHC Sensitive to missing transverse energy carried away by neutral particles: e.g., neutrinos, neutralinos

14. Supersymmetry Searches at LHC LHC reach in supersymmetric parameter space `Typical’ supersymmetric Event at the LHC Can cover most possibilities for astrophysical dark matter

15. 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, Gianotti, JE, Olive, Pape

16. SparticleSignaturesalongWMAPlines Relatively small branching ratios in CMSSM Z h Average numbers of particles per sparticle event τ 3l Battaglia, De Roeck, Gianotti, JE, Olive, Pape

18. Summary of LHCScapabilities … and OtherAccelerators LHC almost `guaranteed’ to discover supersymmetry if it is relevant to the mass problem Battaglia, De Roeck, Gianotti, JE, Olive, Pape

19. Tests of Unification Ideas For gauge couplings For sparticle masses

20. Can one estimate the scale of supersymmetry? Precision Observables in Susy Sensitivity to m1/2 in CMSSM along WMAP lines for different A mW tan β = 10 tan β = 50 sin2θW Present & possible future errors JE + Heinemeyer +Olive +Weiglein

21. MoreObservables tan β = 10 tan β = 50 b → sγ tan β = 10, 50 Bs → μμ gμ- 2 JE + Heinemeyer +Olive +Weiglein

22. Global Fits to Present Data Including mW , sin2θW, b → sγ, gμ - 2 As functions of m1/2 in CMSSM for tan β = 10, 50 JE + Heinemeyer +Olive +Weiglein

23. χ χ2,χ± Global Fitsto Present Data χ3,χ2± τ1 Preferred sparticle masses for tan β = 10 e1 e2 JE + Heinemeyer +Olive +Weiglein

24. t1 t2 Global Fitsto Present Data b1 b2 Preferred sparticle masses for tan β = 10 g A Within reach of LHC! JE + Heinemeyer +Olive +Weiglein

25. Beyond the CMSSM

26. More General Supersymmetric Models • MSSM with more general pattern of supersymmetry breaking: non-universal scalar masses m0 and/or gaugino masses m½ and/or trilinear couplings A0 • Nature of the lightest supersymmetric particle (LSP) • Extended particle content: non-minimal supersymmetric model (NMSSM)

27. Non-Universal Scalar Masses • Different sfermions with same quantum #s? e.g., d, s squarks? disfavoured by upper limits on flavour- changing neutral interactions • Squarks with different #s, squarks and sleptons? disfavoured in various GUT models e.g., dR = eL, dL = uL = uR = eR in SU(5), all in SO(10) • Non-universal susy-breaking masses for Higgses? No reason why not!

28. Non-Universal Higgs Masses (NUHM) • Generalize CMSSM (+) mHi2 = m02(1 + δi) • Free Higgs mixing μ, pseudoscalar mass mA • Larger parameter space • Constrained by vacuum stability

29. Sampling of (m1/2, m0) Planes in NUHM New vertical allowed strips appear JE + Olive + Santoso + Spanos

30. Low-Energy Effective Supersymmetric Theory • Assume universality for sfermions with same quantum numbers (but different generations) • Require electroweak vacuum to be stable (RGE not → negative mass2) up to GUT scale (LEEST) up to 10 TeV (LEEST10) • Qualitatively similar to NUHM not much freedom to adjust squarks/sleptons

31. Sparticles may not be very light Full Model samples ← Second lightest visible sparticle Detectable @ LHC Provide Dark Matter Dark Matter Detectable Directly Lightest visible sparticle → JE + Olive + Santoso + Spanos

32. Gravitino Dark Matter?

33. Possible Nature of LSP • No strong or electromagnetic interactions Otherwise would bind to matter Detectable as anomalous heavy nucleus • Possible weakly-interacting scandidates Sneutrino (Excluded by LEP, direct searches) Lightest neutralino χ Gravitino (nightmare for astrophysical detection)

34. Possible Nature of NLSP • NLSP = next-to-lightest sparticle • Very long lifetime due to gravitational decay, e.g.: • Could be hours, days, weeks, months or years! • Generic possibilities: lightest neutralino χ lightest slepton, probably lighter stau • Constrained by astrophysics/cosmology

35. Different Gravitino masses DifferentRegions of SparticleParameterSpace ifGravitino LSP χ NLSP stau NLSP Density below WMAP limit Decays do not affect BBN/CMB agreement JE + Olive + Santoso + Spanos

36. Neutralino LSP region stau LSP (excluded) Gravitino LSP region tan β fixed by vacuum conditions Minimal Supergravity Model (mSUGRA) More constrained than CMSSM: m3/2 = m0, Bλ = Aλ – 1 Excluded by b  s γ LEP constraints Onmh, chargino JE + Olive + Santoso + Spanos

37. Light Nuclei: BBN vs CMB Good agreement for D/H, 4He: discrepancy for 7Li? Observations Calculations Cyburt + Fields + Olive + Skillman

38. Constraints on Unstable Relics • 7Li < BBN? • Effect of relic decays? • Problems with D/H • 3He/D too high! • Interpret as upper limits on abundance of metastable heavy relics JE + Olive + Vangioni

39. DifferentRegions of SparticleParameterSpace ifGravitino LSP χ NLSP stau NLSP Density below WMAP limit Decays do not affect BBN/CMB agreement JE + Olive + Santoso + Spanos

40. CMSSM Benchmarks GDM Benchmarks Regions Allowedin Different Scenarios forSupersymmetryBreaking NUHM Benchmarks with neutralino NLSP with stau NLSP De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

41. Spectra inNUHM and GDMBenchmarkScenarios Typical example of non-universal Higgs masses: Models with gravitino LSP Models with stau NLSP De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

42. Properties of NUHM and GDM Models • Relic density ~ WMAP in NUHM models • Generally < WMAP in GDM models Need extra source of gravitinos at high temperatures, after inflation? • NLSP lifetime: 104s < τ < few X 106s De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

43. χh, χZ may be large in NUHM Neutralino Masses and Decay Modes χh, χZ small in CMSSM De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

44. Final States in GDM Models with Stau NLSP • All decay chains end with lighter stau • Generally via χ • Often via heavier sleptons • Final states contain 2 staus, 2 τ, often other leptons De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

45. Kinematic Distributions: Point ε • Staus come with many jets & leptons with pT hundreds of GeV, produced centrally De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

46. Kinematic Distributions: Point ζ • Staus come with many jets & leptons with pT hundreds of GeV, produced centrally De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

47. Stau Mass Measurements by Time-of-Flight • Event-by-event accuracy < 10% • < 1% with full sample De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198

48. Numbers of Visible Sparticle Species At different colliders

49. Slepton Trapping at the LHC? If stau next-to-lightest sparticle (NLSP) may be metastable may be stopped in detector/water tank? Trapping rate Kinematics Feng + Smith Hamaguchi +Kuno + Nakaya + Nojiri

50. Stau Momentum Spectra • βγ typically peaked ~ 2 • Staus with βγ < 1 leave central tracker after next beam crossing • Staus with βγ < ¼ trapped inside calorimeter • Staus with βγ < ½ stopped within 10m • Can they be dug out? De Roeck, JE, Gianotti, Moortgat, Olive + Pape: hep-ph/0508198