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LHC / ILC / Cosmology Interplay Sabine Kraml (CERN)

LHC / ILC / Cosmology Interplay Sabine Kraml (CERN). WHEPP-9, Bhubaneswar, India 3-14 Jan 2006. Outline. Introduction Relic density of WIMPs SUSY case as illustrative example Neutralino dark matter Requirements for collider tests Implications of CP violation Conclusions.

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LHC / ILC / Cosmology Interplay Sabine Kraml (CERN)

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  1. LHC / ILC / Cosmology InterplaySabine Kraml (CERN) WHEPP-9, Bhubaneswar, India 3-14 Jan 2006

  2. Outline • Introduction • Relic density of WIMPs • SUSY case as illustrative example • Neutralino dark matter • Requirements for collider tests • Implications of CP violation • Conclusions WHEPP-9 Bhubaneswar

  3. What is the Universe made of? • Cosmological data: • 4% ±0.4% baryonic matter • 23% ±4% dark matter • 73% ±4% dark energy • Particle physics: • SM is incomplete; expect new physics at TeV scale • NP should provide the DM • Discovery at LHC, precision measurements at ILC ? WHEPP-9 Bhubaneswar

  4. Dark matter candidates Neutralino, gravitino, axion, axino, lightest KK particle, T-odd little Higgs, branons, Q-balls, etc., etc... New Physics WHEPP-9 Bhubaneswar

  5. WIMPs (weakly interacting massive particles) • DM must be stable, electrically neutral, weakly and gravitationally interacting • WIMPs are predicted by most BSM theories • Stable as result of discrete symmetries • Produced as thermal relic of the Big Bang • Testable at colliders! Neutralino, gravitino, axion, axino, LKP, T-odd Little Higgs, branons, Q-balls, etc., ... WHEPP-9 Bhubaneswar

  6. Relic density of WIMPs • Early Universe dense and hot; WIMPs in thermal equilibrium • Universe expands and cools;WIMP density is reduced through pair annihilation; Boltzmann suppression: n~e-m/T • Temperature and densitytoo low for WIMP annihilation to keep up with expansion rate → freeze out Final dark matter density: Wh2 ~ 1/<sv> Thermally avaraged cross section of all annihilation channels WMAP: 0.094 < Wh2 < 0.129 @ 2s WHEPP-9 Bhubaneswar

  7. Collider tests of WIMPs • Generic WIMP signature at LHC: jets (+leptons) + ETmiss • Great for discovery; resolving the nature of the WIMP however not obvious • Need precision measurements of masses, couplings, quantum numbers, .... → ILC LHC WMAP ILC WHEPP-9 Bhubaneswar

  8. Neutralino-LSP in the MSSM WHEPP-9 Bhubaneswar

  9. Minimal supersymmetric model • SUSY = Symmetry between fermions and bosons • If R-parity is conserved the lightest SUSY particle (LSP) is stable → LSP as cold dark matter candidate mix to 2 charginos + 4 neutralinos WHEPP-9 Bhubaneswar

  10. Neutralino system Gauginos Higgsinos Neutralino mass eigenstates → LSP WHEPP-9 Bhubaneswar

  11. Neutralino relic density Specific mechanisms to get relic density in agreement with WMAP 0.094 < Wh2 < 0.129 puts strong bounds on the parameter space WHEPP-9 Bhubaneswar

  12. mSUGRA parameter space • GUT-scale boundary conditions: m0, m1/2, A0 [plus tanb, sgn(m)] • 4 regions with right Wh2 • bulk (excl. by mh from LEP) • co-annihilation • Higgs funnel (tanb ~ 50) • focus point (higgsino scenario) WHEPP-9 Bhubaneswar

  13. Prediction of <sv> from colliders:What do we need to measure? • LSP mass and decomposition bino, wino, higgsino admixture • Sfermion masses (bulk, coannhilation) or at least lower limits on them • Higgs masses and widths: h,H,A • tanb With which precision? WHEPP-9 Bhubaneswar

  14. What do we need to measure with which precision:Coannihilation with staus, DM<10 GeV ~ • DM(stau-LSP) to 1 GeV • Precise sparticle mixings • Difficult at LHC; soft tau´s! • Achievable at ILC: • Stau mass at threshold Bambade et al, hep-ph/040601 • Stau and Slepton masses Martyn, hep-ph/0408226 • Stau-neutralino mass difference Khotilovitch et al, hep-ph/0503165 Beam polarization essential! [Allanach et al, hep-ph/0410091] WHEPP-9 Bhubaneswar

  15. Golden decay chain at LHC • Stau coannihilation region: leptons will mostly be taus • Small stau-LSP mass difference DM ≤ 10 GeV leads to soft t´s • Difficult to measure mttkinematic endpoint for mass determination WHEPP-9 Bhubaneswar

  16. Determination of slepton and LSP massesat the ILC [Martyn, hep-ph/0408226] WHEPP-9 Bhubaneswar

  17. Determination of the neutralino systemLHC+ILC case study for SPS1a:light -inos at ILC; neutralino4 at LHC [Desch et al., hep-ph/0312069] WHEPP-9 Bhubaneswar

  18. What do we need to measure with which precision:Higgsino LSP, m ~ M1,2 Fractional accuracies needed • Annihilation into WW and ZZ via t-channel c± or c0 • Rate determined by higgsino fraction fH=N132+N142 • 1% precision on M1 and m • All neutralinos/charginos; mixing via pol. e+e- Xsections • LHC: discovery via 3-body gluino decays / Drell-Yang [Allanach et al, hep-ph/0410091] WHEPP-9 Bhubaneswar

  19. Scan of focus point scenario, LCC2 m0 = 3280 GeV, m1/2 = 300 GeV, A0 = 0, tanb = 10 [J.L. Feng et al., ALCPG] WHEPP-9 Bhubaneswar

  20. What do we need to measure with which precision:Annihilation through Higgs Fractional accuracies needed • Mainly cc→ A →bb • CP even H exchange is P-wave suppressed • mcandmAto 2%-2‰ • (mA-2mc) and m to 5% • A width to 10% g(Acc)~N132-N142, g(Abb)~hb, .... [Allanach et al, hep-ph/0410091] WHEPP-9 Bhubaneswar

  21. Influence of mA on evaluation of Wh2 → large uncertainty if lower limit on mA is not >> 2 mLSP [Birkedal et al, hep-ph/0507214] WHEPP-9 Bhubaneswar

  22. e+e_→ HA • A not produced in Higgs-Strahlung, need e+e_ → HA • H,A masses to ~1 GeV; limitation by kinematics! • Widths only to 20%-30% • Production in gg mode can help a lot [Heinemeyer et al., hep-ph/0511332] WHEPP-9 Bhubaneswar

  23. Heavy Higgses at LHC H/A in cascade decays WHEPP-9 Bhubaneswar

  24. For a precise prediction of Wh2 compatible with WMAP acurracy we need precision measurements of most of the SUSY spectrum → LHC/ILC synergy WHEPP-9 Bhubaneswar

  25. So far considered CP conserving MSSM What if CP is violated? [we actually need new sources of CP violation beyond the SM for baryogenesis] WHEPP-9 Bhubaneswar

  26. CP violation • In the general MSSM, gaugino and higgsino mass parameters and trilinear couplings can be complex: • Important influence on sparticle production and decay rates → Expect similar influence on <sv> NB1: M2 can also be complex, but its phase can be rotated away. NB2: CPV phases are strongly constrained by dipole moments; we set fm=0 and assume very heavy 1st+2nd generation sfermions WHEPP-9 Bhubaneswar

  27. CP violation: Higgs sector • Non-zero phases induce CP violation in the Higgs sector through loops → mixing of h,H,A: • Couplings to neutralinos: WHEPP-9 Bhubaneswar

  28. Previous studiesof neutralino relic density with CP violation WHEPP-9 Bhubaneswar

  29. CPV analysis with micrOMEGAs M1 = 150, M2 = 300, At = 1200 GeV, tanb = 5 masses of 3rd gen: 500 GeV, 1st+2nd gen: 10 TeV • bino-like LSP, m ~ 150 GeV • Wh2 < 0.129 needs annihilation through Higgs • Scenario 1: m = 500 GeV → small mixingin Higgs sector • Scenario 2: m = 1 TeV → large mixing in Higgs sector Higgs mixing ~ Im(Atm) [Belanger, Boudjema, SK, Pukhov, Semenov, in: LesHouches‘05] WHEPP-9 Bhubaneswar

  30. CPV with micrOMEGAs WHEPP-9 Bhubaneswar

  31. Scenario 2 Key parameter is distance from pole WHEPP-9 Bhubaneswar

  32. Recall Higgs funnels in mSUGRA mA= WHEPP-9 Bhubaneswar

  33. Higgs funnel with large Higgs CP-mixing h2 h3 h3 h3 Green bands: 0.094<Wh2<0.129 dmi = mhi - 2mLSP, i=2,3 WHEPP-9 Bhubaneswar

  34. Higgs funnel with large Higgs CP-mixing h2 h3 h3 h3 Green bands: 0.094<Wh2<0.129 WHEPP-9 Bhubaneswar

  35. Higgs funnel with large Higgs CP-mixing h3 Green bands: 0.094<Wh2<0.129 dmi = mhi - 2mLSP, i=2,3 WHEPP-9 Bhubaneswar

  36. CP violation • is a very interesting option • can have order-of-magnitude effect on Wh2 • needs to be tested precisely • However: computation of annihilation cross sections at only at tree level; radiative corrections may be sizeable! WHEPP-9 Bhubaneswar

  37. Assume we have found SUSY with a neutralino LSP and made very precise measurements of all relevant parameters: What if the inferred Wh2 is too high? WHEPP-9 Bhubaneswar

  38. Solution 1:Dark matter is superWIMP e.g. gravitino or axino WHEPP-9 Bhubaneswar

  39. Solution 2:R-parity is violated after all • RPV on long time scales • Late decays of neutralino LSP reduce the number density; actual CDM is something else • Very hard to test at colliders • Astrophysics constraints? WHEPP-9 Bhubaneswar

  40. Solution 3:Cosmological assumptions are wrong • Our picture of dark matter as a thermal relic from the big bang may be to simple • The early Universe may have evolved differently • .... • .... • .... WHEPP-9 Bhubaneswar

  41. Conclusions: • We expect new physics beyond the SM • to show up at the TeV energy scale • to provide the dark matter of the Universe • Using the example of neutralino dark matter I have shown that precison measurements at both LHC+ILC are necessary to pin down the nature and properties of the dark matter Wh2 ~ 1/<sv> from LHC/ILC ↔ WMAP acurracy • Direct detection in addition to pin down DM WHEPP-9 Bhubaneswar

  42. LHC WMAP ILC Accuracies of determining the LSP mass and its relic density [Alexander et al., hep-ph/0507214] WHEPP-9 Bhubaneswar

  43. What if only part of the spectrum is accessible? • Part of the spectrum may escape detection • Too heavy sparticles, only limits on masses • Not enough sensitivity, e.g. H,A • Only LHC data available, .... • Model assumptions, fits of specific models, etc, to obtain testable predicions [or to test models] • Famous example: Fit of mSUGRA to LHC data at SPS1a Need precise predictionswithin models of SUSY breaking WHEPP-9 Bhubaneswar

  44. Comparison of SUSY spectrum codes • Computation of SUSY spectrum with 4 state-of-the-art SUSY codes: Isjet,Softsusy,Spheno,Suspect 2loop RGEs + 1loop threshold corrections, 1loop corr. to Yukawa couplings, ... • Computation of relic desity with micrOMEGAs • Mapped mSUGRA parameter space for • differences in predictions of Wh2 • differences in WMAP exclusions due to spectrum uncertainties [Belanger, SK, Pukhov, hep-ph/0502079] WHEPP-9 Bhubaneswar

  45. Uncertainties from sparticle mass predictions O(1%) moderate parameters, stau coannihilation Stau-LSP mass difference! d(DM)~1 GeV →dW~10% Contours of Wh2=0.129 [Belanger, SK, Pukhov, hep-ph/0502079] WHEPP-9 Bhubaneswar

  46. Uncertainties from sparticle mass predictions: large tanb and the Higgs funnel [Belanger, SK, Pukhov, hep-ph/0502079] WHEPP-9 Bhubaneswar

  47. There is need to improve computations and tools in order to match acurracies required by WMAP/Planck Improvements in spectrum computations are discussed in [Baer, Ferrandis, SK, Porod, hep-ph/0511123] WHEPP-9 Bhubaneswar

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