1. Neutralino Dark Matter Yeong Gyun Kim (Korea Univ.) I.Evidence for Dark Matter II.Dark Matter Candidates III.Detection of Neutralino WIMP IV.Conclusions

2. What is Dark Matter ? : stuff that neither emits nor absorbs detectable EM radiation : the existence can be inferred by its gravitational effects on visible celestial body  Motion of Galaxies in Clusters  Galactic Rotation Curves  Gravitational Lensing  Temperature fluctuation of CMBR  …… I.Evidence for Dark Matter

3.  Observed the Coma cluster of galaxies in 1933: Fritz Zwicky (1898-1974)  Motions of galaxies in clusters  Found the galaxies move too fast to be confined in the cluster by the gravitational attraction of visible matter alone. The central 1Mpc of Coma cluster in optical Dark Matter in cluster

4. Galactic Rotation Curves Vera Rubin (1928-)  In 1970s, they found ‘flat’ rotation curves. Dark Matter in galaxy

5. Cosmic Microwave Background Anisotropies WMAP satellite

6. Matter/Energy density in the Universe Non-Baryonic Dark Matter Dark Energy (Cosmological constant) Baryonic Dark Matter

7. ( What is the Dark Matter made of ? )  MACHOs (MAssive Compact Halo Objects)  Baryonic Dark Matter candidates ; Jupiters, brown dwarfs, white dwarfs, neutron stars, black hole….  Hydrogen Gas - cold gas : 21cm line radiation - hot gas : X-ray emission …  Dusts – extinction, reddening II. Dark Matter Candidates Gravitaional microlensng (EROS, MACHO)

8.  SM neutrinos (hot DM)  Axion  Kaluza-Klein states  Non-Baryonic Dark Matter candidates  Wimpzillas (superheavy DM)  …. ….  Lightest Supersymmetric Particle - Neutralino - Gravitino - Axino ; WMAP + 2dFGRS (0.0005 < )

9. Relic density of WIMPs Time evolution of the number density of WIMPs H : Hubble constant : thermally averaged annihilation cross section of WIMP WIMP : Weakly Interacting Massive Particle : equilibrium number density

10. Freeze out at If

11. Minimal Supersymmetric Standard Model (MSSM) SM fields plus an extra Higgs doublet and their superpartners SU(3) x SU(2) x U(1) gauge symmetry and Renormalizability R-parity conservation (to avoid fast proton decay) ( B: baryon number, L: lepton number S: spin ) = +1 for ordinary particles = -1 for their superpartners Soft Supersymmetry Breaking LSP is STABLE !

12. Neutralino mass matrix In the basis : Bino, Wino mass parameters : Higgsino mass parameter : ratio of vev of the two neutral Higgs  Lightest Neutralino = LSP in many cases (WIMP !! )

13. Neutralino Annihilation channels etc.

14. Minimal Supergravity Model  Unification of the gauge couplings at GUT scale  Universal soft breaking parameters at GUT scale m : universal scalar mass M : universal gaugino mass A : universal trilinear coupling  Radiative EW symmetry breaking Free parameters ( m,M,A, )

15. These conditions imply that at EW scale Bino-like Wino-like and Large

16. Overview of the allowed regions of mSUGRA parameter space by the Relic density of Neutralino WIMP 1. Bulk region : at low m0 and m1/2 : t-channel slepton exchange 2. Stau co-annihil. region : at low m0 where : neutralino-stau coannihilation 3. Focus point region : at large m0 where mu is small : a sigificant higgsino comp. 4. A-annihilation region : at largewhere

17. The Relic density of Neutralino WIMP vs. Large Hadron Collider (LHC) LHC : not only a discovery machine but also a precision physics tool  proton-proton at 14 TeV  10 fb^-1 integrated luminosity per year (first three years)  100 fb^-1 per year (designed)  A Case Study : Bulk region scenario  lies at low m0 and m1/2  LSP pair annihilation dominated by t-channel slepton exchange  LSP is Bino-like

18. The relic density of Bino LSP by t-channel right-handed slepton exchange

19. (Drees, YGK, Nojiri, Toya, Hasuko, Kobayashi 2001) M 100 500 200 400  measurepredict

20. Precision measurements of sparticle masses at the LHC When the cascade decay is open, a clean SUSY signal is l l + jets + missing events.

21. (Bachacou, Hinchliffe, Paige 2000) (for “point 5”, M=300 GeV and m=100 GeV)

22. From various end point measurement, ~ 10 % measurement of ~ 20 % prediction of (for “ point 5 ”, M=300 GeV and m=100 GeV)

23. : Confirmation of Neutralino DM : Other DM components ? : Low reheating temperature ?  Cases

24.  Direct detection Local Dark Matter density Maxwellian velocity distribution Local Flux of Dark Matter III. Detection of Neutralino WIMP

25. Principles of WIMP detection Elastic scattering of a WIMP on a nucleus inside a detector The recoil energy of a nucleus with mass For This recoil can be detected in some ways : Electric charges released (ionization detector) Flashes of light produced (scintillation detector) Vibrations produced (phonon detector)

26. Low energy effective Lagrangian for neutralino-quark int. scalar interaction spin-dep. interaction The other terms are velocity-dependent contributions and can be neglected in the non-relativistic limit for the direct detection. The axial vector currents are proportional to spin operators in the non-relativistic limit.

27. : the quark spin content of the nucleon  Spin-dep. Neutralino-Neucleus cross-section where (J : the spin of the nucleus) : the expectation values of the spin content of the nucleus : depends on the target nucleus for : reduced mass

28.  Scalar Neutralino-Neucleus cross-section whereA : the atomic weight, Z : the nuclear electric charge

29. In most instances, : the scalar (spin-independent) cross section scales with the atomic weight, in contrast to the spin-dependent cross section. The scalar interaction almost always dominates for nuclei with A > 30. : For, either interaction can dominate, depending on the SUSY parameters. : has predominantly spin-independent interactions.  vs.

30.  mSUGRA model ( A=0 and m,M < 1TeV ) Higgs and sparticle masses and bounds included. Required that Neutralino is LSP (S.Baek, YGK, P.Ko 2004 ) Scalar cross section of Neutralino-proton scattering

31.  Non-universal Higgs mass Model (NUHM)  Parameterize the non-universality in the Higgs sector at GUT scale  The above modifications of mSUGRA boundary cond. lead to the change of and at EW scale.

32. mSUGRANUHM

33. mSUGRANUHM

34. Non-Universal Higgs Mass Model

35. Non-Universal Higgs Mass Model

36.  A specific D-brane Model  the SM gauge groups and 3 generations live on different Dp branes.  In this model, scalar masses are not completely universal and gaugino mass unificaion can be relaxed.  the string scale is around GeV rather than GUT scale. Free parameters:

37. A D-brane Model

38.  Indirect detection of Neutralino WIMP (neutrino telescopes : SuperK, Amanda, Antares, IceCube …)  Neutralino in the galactic halo can be captured into SUN (or Earth) by Neutralino-nucleus scattering  The neutrinos can be detected via conversion in neutrino telescope  The accumulated Neutralinos annihilate into SM particles, which ultimately yields energetic neutrino flux  The muon flux strongly depends on Neutralino-nucleus scattering

39. Muon Flux vs. mSUGRA model ( A=0 and m,M < 1TeV ) from the Sunfrom the Earth (S.Baek, YGK, P.Ko PRELIMINARY)

40. Muon Flux vs. Non-Universal Higgs Mass Model from the Sunfrom the Earth (S.Baek, YGK, P.Ko PRELIMINARY)

41. Muon Flux vs. Non-Universal Higgs Mass Model from the Sunfrom the Earth (S.Baek, YGK, P.Ko PRELIMINARY)

42. Muon Flux vs. A D-brane Model (S.Baek, YGK, P.Ko PRELIMINARY) from the Earth from the Sun

43. IV. Conclusion

44. Backup Slides

45. Acoustic Peak Region, (90 < l < 900) : described by the physics of photon-baryon fluid responding to fluctuation in the gravitational potential produced by the Dark Matter.  The Position of the First Peak Geometry of the universe.  The Amplitude of the First Peak depends on Omega_b h^2, Omega_m h^2 Increasing O_m h^2 decreases the peak height. (reducing the effects of “radiation driving”)  The Amplitude of the Second Peak Increasing omega_b h^2 decreases its height (increasing the inertia in the photon-baryon fluid) Increasing n_s increases the height of the peak relative to the first.  The Amplitude of the Third Peak Measuring the third peak helps mostly in measuring n_s. ( long l base line makes the ratio to the first peak sensitive to n_s) Age of the universe in a flat geometry

46. If the LSP is bino-like, slepton masses are moderate and one is far away from s-channel poles, the LSP mass density is essentially determined by t-channel right-handed slepton exchange. 1.A pure bino couples only to fermion and sfermion, or Higgs and higgsino. Higgsino exchange is suppressed for 2. in mSUGRA, therefore right-handed slepton exchange is least suppressed by large mass in the propagator. 3. The hypercharges of sleptons satisfy the relation therefore when sfermion masses are equal.

47. III. decays in MSSM In the Standard Model the decay proceeds through Z penguin and W exchange box diagrams. the decay is helicity suppressed due to angular momentum conservation. Current Experimental Limit (90% CL) (CDF) (D0, FPCP04)

48. In the MSSM (Babu,Kolda 2000) Fermion mass eigenstates can be different from the Higgs interaction eigenstates. This generates Higgs-mediated FCNCs.

49.  vs.  Both observables increase as increases.  Smaller Higgs masses give larger observable values.

50. Experimental Results (Munoz, hep-ph/0309346)

51. mSUGRA model ( A=0 and m,M < 1TeV ) Higgs and sparticle mass and bounds included.

52. Non-Universal Higgs Mass Model

57. A D-brane Model

58. Muon Flux from the SUN vs.

61. V. Conclusions We investigated the correlation between scalar cross section for neutralino-proton scattering and branching ratio of decays in mSUGRA, Non-Univ. Higgs mass and a D-brane model. Both observables increase as increase and decrease. Therefore, we find a positive correlation between two observables, though the detailed predictions differ between models. Current upper limit on the branching ratio already puts strong constraint on the model parameter space which could lead to quite large neutralino-proton scattering cross section.