Cosmology and the ILC

1. Cosmology and the ILC G. Bélanger LAPTH- Annecy

2. PLAN • Cosmology <-> colliders • Dark matter • Baryon asymmetry • Dark energy? • Neutralino dark matter • Precision studies • Correlation with direct/indirect detection • Dark matter : beyond MSSM • Electroweak Baryogenesis • Conclusions

3. What is the universe made of? • Although evidence for dark matter has been around for a while both at scale of galaxy clusters (Zwicky 1933) and of galaxies (rotation curves), in 2003 with CMB anisotropy map achieve precise determination of cosmological parameters

4. What is the universe made of? • In recent years : new precise determination of cosmological parameters • Data from CMB (WMAP) agree with the one from clusters and supernovae • Dark matter: 23+/- 4% • Baryons: 4+/-.4% • Dark energy 73+/-4% • Neutrinos < 1%

5. Search for dark matter • In 2003 WMAP has measured relic density +/-15% (2σ) • This year new results • In 2007 PLANCK will start operating, goal is to reach +/- 5-6% on relic density(2σ) • In 2008 LHC will start, might have discovery and measurements of supersymmetric particles (or other NP) within a few years • In the meantime direct detection and indirect detection experiments continue to run with improved detectors HEPAP subpanel report on future particle colliders

6. Dark matter Related to physics at weak scale New physics at weak scale can also solve EWSB Many possible solutions: new particle that exist in some NP models, not necessarily designed for DM Dark energy Related to Planck scale physics NP for dark energy might affect cosmology and dark matter Neutrinos (they exist but only small component of DM) Supersymmetry with R parity conservation Neutralino LSP Gravitino Axino Kaluza-Klein dark matter UED (LKP ) LZP is neutrino-R (in Warped Xdim models with matter in the bulk) Branons Little Higgs with T-parity …… What is dark matter/dark energy

7. Relic density of wimps • In early universe WIMPs are present in large number and they are in thermal equilibrium • As the universe expanded and cooled their density is reduced through pair annihilation • Eventually density is too low for annihilation process to keep up with expansion rate • Freeze-out temperature • LSP decouples from standard model particles, density depends only on expansion rate of the universe Freeze-out

8. Relic density • A relic density in agreement with present measurements Ωh2 ~0.1 requires typical weak interactions cross-section

9. Accuracy on relic density of LSP • Goal is to reach at least the same precision on the prediction of the relic density as the experimental one • +X • Right now depending on particle physics models (even if only consider supersymmetry) predictions vary by orders of magnitude • For different cosmological model also vary by orders of magnitude • Changes in H affect the freeze-out temperature • New terms in Boltzmann equations

10. Dark matter : cosmo/astro/pp • Wimps have roughly right value for relic density • Neutralinos are wimps but not all SUSY models are acceptable • Precise measurement of relic density  constrain models • Generic class of SUSY models that are OK • Direct/Indirect detection : search for dark matter  establish that new particle is dark matter  constrain models • Colliders : which model for NP/ prediction for σv/confront cosmology • LHC: discovery of new physics, dark matter candidate and/or new particles • ILC: extend discovery potential of LHC + precision measurements • How well this can be done strongly depends on model for NP

11. Neutralino LSP • Prediction for relic density depend on parameters of model • Mass of neutralino LSP • Nature of neutralino : determine the coupling to Z, h, A … • M1 <M2< bino •  <M1,M2 Higgsino • M2<M1<  Wino

12. Neutralino annihilation • 3 typical mechanisms for χannihilation • Bino annihilation into ff • σ ~ mχ2/mf 4 • Mixed bino-Higgsino (wino) • Coupling depends on Z12,Z13,Z14, mixing of LSP • Annihilation near resonance (Higgs)

13. Neutralino annihilation • 3 typical mechanisms for χannihilation • Bino annihilation into ff • σ ~ mχ2/mf 4 • Mixed bino-Higgsino (wino) • Coupling depends on Z12,Z13,Z14 • Annihilation near resonance (Higgs) • Need some coupling to A, some mixing with Higgsino

14. Coannihilation • If M(NLSP)~M(LSP) then maintains thermal equilibrium between NLSP-LSP even after SUSY particles decouple from standard ones • Relic density depends on rate for all processes involving LSP/NLSP  SM • All particles eventually decay into LSP, calculation of relic density requires summing over all possible processes • Important processes are those involving particles close in mass to LSP • Public codes to calculate relic density: micrOMEGAs, DarkSUSY, IsaRED Exp(- ΔM)/T

15. Neutralino co-annihilation • Can occur with all sfermions, gauginos • Bino LSP (sfermion coannihilation) • Higgsino LSP- coannihilation with chargino and neutralinos

16. What happens in generic SUSY models, does one gets the right value for the relic density? • mSUGRA (only 5 parameters) • M0, M1/2, tan β, A0,  • Other models  MSSM (at least 19 parameters)

17. The mSUGRA case Mt=178 • Theoretical assumption: the model is known mSUGRA (CMSSM) • Useful case study contains (almost) all typical processes for neutralino (co)-annihilation • bino – LSP :annihilation in fermion pairs • In most of mSUGRA parameter space • Works well for light sparticles but hard to reconcile with LEP/Higgs limit (small window open) • Sfermion coannihilation • Staus or stops • More efficient, can go to higher masses • Mixed bino-Higgsino: annihilation into W/Z/t pairs • Resonance (Z, light/heavy Higgs) Mt=175GeV

18. The mSUGRA case -WMAP • Bino – LSP • Sfermion Coannihilation • Mixed Bino-Higgsino • Annihilation into W pairs • In mSUGRA unstable region, mt dependence, works better at large tanβ • Resonance (Z, light/heavy Higgs) • LEP constraints for light Higgs/Z • Heavy Higgs at large tanβ (enhanced Hbb vertex)

19. WMAP and SUSY dark matter • The mSUGRA model seems fine-tuned (either small ΔM or Higgs resonance) . • The LSP is bino • Not generic of other SUSY models, a good dark matter candidate is a mixed bino/Higgsino …. • In particular, main annihilation into gauge boson pairs works well for Higgsino fraction ~25% • The mixed bino/Higgsino can be found in many models: mSUGRA (focus), non-universal SUGRA, string inspired (moduli-dominated) models, split SUSY, NMSSM….

20. Which scenario? Potential for SUSY discovery at LHC/ILC • Some of these scenarios will be probed at LHC/ILC and/or direct /indirect detection experiments • Corroborating two signals SUSY dark matter • LHC • Squarks, gluinos < 2- 2.5 TeV • Sparticles in decay chains • mSUGRA: probe significant parameter space, heavy Higgs difficult, large m0-m1/2 also. • Other models : similar reach in masses • ILC • Production of any new sparticles within energy range • Extend the reach of LHC in particular in “focus point” of mSUGRA Baer et al., hep-ph/0405210

21. Probing cosmology using collider information • Within the context of a given model can one make precise predictions for the relic density at the level of WMAP(10-15%) and even PLANCK (3-6%) (2007) therefore test the underlying cosmological model. • Assume discovery SUSY, precision from LHC? • Precision from ILC? • Answer depends strongly on underlying NP scenario, many parameters enter computation of relic density, only a handful of relevant ones for each scenario – work is going on in North America, Asia and Europe both for LHC and ILC, within mSUGRA or MSSM • Moroi, Bambade, Richard, Zhang, Martyn, Tovey, Polesello, Lari, D. Zerwas, Allanach, Belanger, Boudjema, Pukhov, Battaglia, Birkedal, Gray, Matchev, Alexander, Fields, Hertz, Jones, Meyraiban, Pivarski, Peskin, Dutta, Kamon, Arnowitt, Khotilovith, Nojiri…

22. Precision on relic density • Concentrate on MSSM, although choice of case study done within mSUGRA • Examples of typical scenarios • SPA1A (bulk+coannihilation) • Coannihilation • LCC2 (Higgsino or focus) • Heavy Higgs

23. One example: SPA1A M0=70, M1/2=250, A0=-300,tanβ=10 • ‘Bulk’+ stau coannihilation • Annihilation into fermions • Coannihilation with staus • Relevant parameters : LSP mass, couplings, slepton masses • stau-neutralino mass difference (for coannihilation processes)

24. Decay chain Signal: jet +dilepton pair Can reconstruct four masses from endpoint of ll and qll In particular stau-neutralino mass difference Here Δm (NLSP-LSP) = 2.5GeV Mixing in the stau sector obtained from For LSP couplings need 3 masses (χ1χ2χ4) and assume tanβ Assume tanβ known + limit on heavy stau and on heavy Higgs Determination of parameters LHC : SPA1A

25. LHC: SPA1A • LHC: roughly the WMAP precision can be achieved within MSSM if good precision on position of ττ edge • Also important to measure sfermion/neutralino parameters and setting limits on Higgs, other coannihilation particles… Nojiri et al, hep-ph/0512204

26. LHC: SPA1A • LHC: roughly the WMAP precision can be achieved within MSSM if good precision on position of ττ edge • Also important to measure sfermion/neutralino parameters and setting limits on Higgs, other coannihilation particles… Nojiri et al, hep-ph/0512204

27. Even in this favourable scenario, LHC can reach only roughly WMAP precision if no underlying assumption about mSUGRA • Other mSUGRA and even more so other MSSM scenarios will be hard for LHC • Need ILC precision • Is that enough?

28. MSSM: stau coannihilation Precision required for ΔΩ/Ω~10% • Challenge: measuring precisely mass difference • Why? Ωh2 dominated by Boltzmann factor exp(- ΔM/T) • Stau-neutralino mass difference need to be measured to ~1 GeV • ILC: can match the precision of WMAP and even better • 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 Allanach et al, JHEP2005

29. Higgsino in MSSM: mSUGRA-inspired focus point • No dependence on mt except near threshold • Relic density depend on 4 neutralino parameters, M1, M2, , tanβ • To achieve WMAP precision on relic density must determine • (M1,) 1% . • tanβ~10% • Is it possible?

30. …. Higgsino LSP • If squarks are heavy difficult scenario for LHC • only gluino accessible, chargino/neutralino in decays • mass differences could be measured from neutralino leptonic decays, • How well can gaugino parameters can be reconstructed? • Light Higgsinos possibly many accessible states at ILC • Baltz, et al , hep-ph/0602187

31. … Higgsino LSP • Recent study of determination of parameters and reconstruction of relic density in this scenario (LCC2) • LHC: not enough precision • ILC: chargino pair production sensitive to bino/Higgsino mixing parameter • ILC: roughly 10% precision on Ωh2 Baltz et al hep-ph/0602187

32. Annihilation through Higgs • In mSUGRA relevant at large tanβ • Important parameters : mass LSP, mA, Γ(A) • Right at the peak, annihilation much too effective Allanach et al, JHEP2005

33. Higgs funnel (LCC4) • Some information on MA is not sufficient to have precise prediction of relic density, must measure also width • In this scenario (MA~410GeV), width can only be measured at ILC-1000 ( ~10%) • Leads to ΔΩ/Ω~ 18% M0=380 M1/2=420 tanβ=53

34. Summary - Relic density

35. Complementarity astroparticle/ colliders • Indirect/direct detection can find (some hints from Egret, Hess..) signal for dark matter • Many experiments under way, more are planned • Direct: CDMS, Edelweiss, Dama, Cresst, Zeplin Xenon, Genius… • Indirect: Hess, Veritas, Glast, HEAT, Pamela, AMS, Amanda, Icecube, Antares … • Can check if compatible with some SUSY or other scenario • Complementarity with LHC/ILC: • Establishing that there is dark matter • Probing SUSY dark matter candidates • Models that give good signal in direct/indirect detection (mixed bino/Higgsino LSP) also give signal at ILC • Direct detection: scattering of LSP on nuclei through Higgs/squark exchange • Indirect detection of product of dark matter pair annihilation in space (positrons, photons, neutrinos) • Best signal for hard positrons or hard photons from neutralino annihilation into WW,ZZ • Clear complementarity between (in)direct detection – LHC -ILC

36. LHC+ILC + indirect detection • With measurements from LHC+ILC can we refine predictions for direct/indirect detection? • Consider our Higgsino example (LCC2) • Prediction for annihilation cross-section at v=0 E. Baltz et al hep-ph/0602187

37. Other dark matter candidates • Gravitinos (axinos…) • Universal extra-dimensions : LKP • Warped extra-dimensions: LZP • Little Higgs models: LTP • …

38. Other DM candidates: KK • UED • Minimal UED: LKP is B (1), partner of hypercharge gauge boson • s-channel annihilation of LKP (gauge boson) typically more efficient than that of neutralino LSP • Compatibility with WMAPmeans rather heavy LKP, 500-600 GeV (Tait, Servant) • New calculation show that all coannihilation should be included as well as radiative corrections to masses (Kong, Matchev) • Within LHC range, relevant for > TeV linear collider

39. Other DM candidates: KK • Warped Xtra-Dim (Randall-Sundrum) • GUT model with matter in the bulk • Solving baryon number violation in GUT models  stable Kaluza-Klein particle • Example based on SO(10) with Z3 symmetry: LZP is KK right-handed neutrino • Agashe, Servant, hep-ph/0403143

40. Dark matter in Warped X-tra Dim • Compatibility with WMAP for LZP range 50- >1TeV • LZP is Dirac particle, coupling to Z through Z-Z’ mixing and mixing with LH neutrino • Large cross-sections for direct detection • Signal for next generation of detectors in large area of parameter space • What can be done at colliders : identify model, determination of parameters and confronting cosmology? Agashe, Servant, hep-ph/0403143

41. Other DM candidates: LTP • Little Higgs models with global symmetry broken at TeV scale • light Higgs is a pseudo Nambu-Goldstone boson, • Littlest Higgs model: simplest model but need a discrete symmetry (T-parity) to be consistent with electroweak precision measurements • Heavy photon (partner of hypercharge boson) is LTP • Annihilation through Higgs exchange or coannihilation • Determination of parameters at colliders ? • Precision required on masses expected to be similar to Higgs funnel scenario of MSSM

42. Cosmological scenario • Different cosmological scenario might affect the relic density of dark matter • Example: quintessence • Quintessence contribution forces universe into faster expansion • Annihilation rate drops below expansion rate at higher temperature • Increase relic density of WIMPS • In MSSM: can lead to large enhancements Profumo, Ullio, hep-ph/0309220

43. Baryon asymmetry of universe • Small excess of particles over antiparticles in the universe • Both Big Bang Nucleosynthesis (BBN) and measurements of CMB agree • Conditions to create an excess • Baryon number violation • C and CP violation • Out of thermal equilibrium • Non-vanishing B-L • Need physics Beyond the SM

44. Electroweak baryogenesis • Baryon number generation at electroweak phase transition • Need strong first order phase transition • Finite temperature effective potential • V= AT2φ2 - ET φ3+ λφ4 , condition : 2E/λ>1 • In SM requires Higgs mass < 50 GeV • New physics solution: • Bosonic loops: light stops in MSSM (Carena et al..) • New strongly coupled fermions • Modification of tree-level potential • NMSSM, SUSY with U(1)’ (Kang et al, 2005) • Higher-order operators in Higgs-potential • Kanemura, Okada, Senaha (2004) , Grojean, Servant, Wells (2004)

45. EW baryogenesis and ILC • Whether electroweak baryogenesis is realised with new particles or modification of the Higgs sector, there will be signals at colliders (and edm) • Light RH stop in MSSM + light neutralino/ chargino +CP • Light RH stop for 1st order phase transition • New CP phases from  and A • Discovery potential at Tevatron/LHC/ILC + edm • Signals for CP violation at ILC • Prediction for relic density of DM in this model

46. Scenario with light stop • Can explain both dark matter and baryon asymmetry • ILC extend discovery range of Tevatron • Freitas et al, Snowmass • Improvement of edm limit -> strong constraint on model • Balazs et al 2005

47. CP violation and ILC S. Hesselbach, Snowmass • CP even observables can be used to determine phases in MSSM, unambiguous signal from CP- and T-odd asymetries at ILC • Many studies with neutralino/ chargino production and decays • T-odd triple product • CP odd asymmetries with transverse beam polarization

48. Relic density and phases • Strong dependence on phases even after taking into account shifts in masses • For example, in stop coannihilation scenario ~ factor 2 • Need to measure precisely spectrum and couplings of LSP (including phases) GB et al, hep-ph/0604150

49. Conclusions and remarks • In most scenarios, LHC will not provide sufficient precise information to probe cosmology  large uncertainties from particle physics models remain. • ILC fare much better especially without underlying theoretical assumption • More detailed studies needed both in MSSM and for other dark matter candidates • Note that it might also be possible with collider data to show that expected relic density is below WMAP pointing towards different cosmological model or other dark matter candidate • In this case correlation with signals from direct/indirect detection important (expect large signals for Higgsino LSP) • ILC can also test models of baryogenesis

50. Higgs self-coupling and EWBG • Electroweak baryogenesis requires a large correction to the finite temperature effective potential. • The zero temperature potential is also expected to receive a large correction. • In particular modification of triple Higgs boson coupling  can be measured at ILC • For example in 2HDM and MSSM. S.Kanemura, Y. Okada, E.Senaha, 2004