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Neutralino Dark Matter in the GUT-less CMSSM

Neutralino Dark Matter in the GUT-less CMSSM. Pearl Sandick University of Minnesota. First Glimpse of Dark Matter. 1933: Fritz Zwicky Used Doppler shift to measure the peculiar velocities of galaxies at the edge of the Coma Cluster

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Neutralino Dark Matter in the GUT-less CMSSM

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  1. Neutralino Dark Matter in the GUT-less CMSSM Pearl Sandick University of Minnesota Fermilab Theoretical Astrophysics Seminar

  2. First Glimpse of Dark Matter • 1933: Fritz Zwicky • Used Doppler shift to measure the peculiar velocities of galaxies at the edge of the Coma Cluster • Assuming virial equilibrium, found that most of the mass of the cluster must not be visible • Analysis has been repeated many times: Different clusters, same (qualitative) result! Fermilab Theoretical Astrophysics Seminar

  3. Dark Matter Component Rotation Curves • Newtonian Mechanics: So outside of the luminous disk, expect Instead, observe Fermilab Theoretical Astrophysics Seminar

  4. State of the Art • X-ray measurements (Chandra) • [weak] gravitational lensing • Bullet Cluster • WMAP Clowe et al. (2006) NASA/WMAP Science Team Fermilab Theoretical Astrophysics Seminar

  5. oscillations/mass GR + EM Strong CP Problem SUSY neutralinos DM + DE extra dimensions restores parity produced at end of inflation? What could it be? Candidates include: neutrinos, axions, KK excitations, Q-balls, gravitinos, neutralinos, axinos, Chaplygin gas, primordial black holes, branons, mirror matter, WIMPzillas… Fermilab Theoretical Astrophysics Seminar

  6. constant So  Weakly Interacting Massive Particles = Neutralinos What makes a good DM candidate? • Stable, Neutral • From WMAP et al.DMh2  0.1 and Fermilab Theoretical Astrophysics Seminar

  7. That is, the maximal symmetry that a theory of particles can have is: Poincaré + Internal + Symmetry that transforms fermions  bosons like color interplay of Poincaré and internal symmetries! required by relativity Why study SUSY? • Haag, Lopuszanski and Sohnius (1975): • Supersymmetry is the only graded Lie algebra that generates symmetries of the S-matrix consistent with relativistic quantum field theory. Fermilab Theoretical Astrophysics Seminar

  8. SM: SUSY: Why study SUSY? • Hierarchy Problem: Why is mH << mP? Classical Higgs Potential: V = mH2 ||2 + ||4 SM requires <>  0, so <> = (-mH2 / 2 )1/2  174 GeV  -mH2  (100 GeV)2 But mH2 gets quantum corrections from particles that interact with the Higgs field! Fermilab Theoretical Astrophysics Seminar

  9. Just right! SUSY Why study SUSY? • Unification of the Gauge Couplings Running (b’s) depends only on particle content of the model. Near miss! SM Fermilab Theoretical Astrophysics Seminar

  10. Particle Zoo MSSM: Minimal Supersymmetric Standard Model Has the minimal particle content possible in a SUSY theory. Fermilab Theoretical Astrophysics Seminar

  11. quarks and squarks Fermions and sfermions leptons and sleptons W boson and wino gauge bosons and gauginos gluon and gluino Neutralinos! B boson and bino Higgs bosons and higgsinos Particle Zoo Fermilab Theoretical Astrophysics Seminar

  12. Caveat: The lightest SUSY particle (LSP) is stable if R-parity is conserved. +1 for SM particles -1 for sparticles R = (-1)3B+L+2S = • Why conserve R-parity? • Stability of proton • Neutron-antineutron oscillations • Neutrino mass • Ad hoc? • SO(10) GUTs • B and L numbers become accidental symmetries of SUSY Another reason to study SUSY: • Neutralinos are an excellent dark matter candidate! • The lightest one may be a stable WIMP with h2  DMh2 Fermilab Theoretical Astrophysics Seminar

  13. Another reason to study SUSY: • Neutralinos are an excellent dark matter candidate! • The lightest one may be a stable WIMP with h2  DMh2 Note: Properties of neutralino LSP will depend on its composition! Fermilab Theoretical Astrophysics Seminar

  14. SUSY Breaking • Don’t observe boson-fermion degeneracy, so SUSY must be broken (How?) • Most general case (MSSM) has > 100 new parameters! • Make some assumptions about SUSY breaking at a high scale, and evolve mass parameters down to low scale for observables • Explicitly add [soft] SUSY-breaking terms to the theory • Masses for all gauginos and scalars • Couplings for scalar-scalar and scalar-scalar-scalar interactions • CMSSM (similar to mSUGRA) • Assume universality of soft SUSY-breaking parameters at MGUT • Free Parameters: m0, m1/2, A0, tan(), sign() Fermilab Theoretical Astrophysics Seminar

  15. Neutralino Relic Density 1. Assume neutralinos were once in thermal equilibrium • Solve the Boltzmann rate equation to find abundance now Fermilab Theoretical Astrophysics Seminar

  16. Be Careful! • Situations when care must be taken to properly calculate (approximate) the relic density: 1. s - channel poles • 2 m  mA 2. Coannihilations • m  mother sparticle 3. Thresholds • 2 m  final state mass Griest and Seckel (1991) Fermilab Theoretical Astrophysics Seminar

  17. Constraints Apply constraints from colliders and cosmology: mh > 114 GeV m± > 104 GeV BR(b  s ) HFAG BR(Bs  +--) CDF (g -- 2)/2 g-2 collab. LEP 0.09  h2  0.12 Fermilab Theoretical Astrophysics Seminar

  18. Focus Point LEP Higgs mass Relaxed LEP Higgs LEP chargino mass 2 < 0 (no EWSB) g--2 suggested region stau LSP Coannihilation Strip CMSSM Fermilab Theoretical Astrophysics Seminar

  19. Rapid annihilation funnel 2m  mA bs B+-- CMSSM Fermilab Theoretical Astrophysics Seminar

  20. tan() CMSSM with >0 and A0=0 0.094 < h2 < 0.129 tan() = 5,10,15,20,25,30, 35,40,45,50,55 Fermilab Theoretical Astrophysics Seminar

  21. CMSSM Summary • (If DM consists mainly of neutralinos), the constraint on the relic density of neutralinos restricts m1/2 and m0 to thin strips of parameter space. • tan() provides leverage. • Most of parameter space is not compatible with measured DM density. Fermilab Theoretical Astrophysics Seminar

  22. GUT-less CMSSM • What if SUSY breaking appears below the GUT scale? • Should the soft breaking parameters be universal below the SUSY GUT scale? • Mixed modulus-anomaly mediated SUSY breaking with KKLT type moduli stabilization (mirage mediation models), warped extra dimensions, … • SUSY broken in a hidden sector (communication to observable sector?) Add new parameter! Scale of universality of the soft breaking parameters: Min Fermilab Theoretical Astrophysics Seminar

  23. M1/2 = 800 GeV Sparticle Mass Evolution • First look at gaugino and scalar mass evolution. • Gauginos (1-Loop): • Running of gauge couplings identical to CMSSM case, so low scale gaugino masses are all closer to m1/2 as Min is lowered. Fermilab Theoretical Astrophysics Seminar

  24. m0 = 1000 GeV Sparticle Mass Evolution • First look at gaugino and scalar mass evolution. • Scalars (1-Loop): • As Min low scale Q, expect low scale scalar masses to be closer to m0. Fermilab Theoretical Astrophysics Seminar

  25. Sparticle Mass (parameter) Evolution • Higgs mass parameter,  (tree level): • As Min low scale Q, expect low scale scalar masses to be closer to m0. • 2 becomes generically smaller as Min is lowered. Fermilab Theoretical Astrophysics Seminar

  26. Mass Evolution with Min • m1/2 = 800 GeV • m0= 1000 GeV • A0 = 0 • tan() = 10 • > 0 Fermilab Theoretical Astrophysics Seminar

  27. Neutralinos and Charginos Must properly include coannihilations involving all three lightest neutralinos! • m1/2 = 800 GeV • m0= 1000 GeV • A0 = 0 • tan() = 10 • > 0 Fermilab Theoretical Astrophysics Seminar

  28. h2 too small! Lowering Min Fermilab Theoretical Astrophysics Seminar

  29. h2 too small! Lowering Min – large tan() Fermilab Theoretical Astrophysics Seminar

  30. Non-zero Trilinear Couplings • A0 > 0  larger weak-scale trilinear couplings, Ai • Large loop corrections to  depend on Ai, so  is generically larger over the plane than when A0 = 0. • Also see stop-LSP excluded region Fermilab Theoretical Astrophysics Seminar

  31. Direct Detection If neutralinos are DM, they are present locally, so will occasionally bump into a nucleus. Effective 4-fermion lagrangian for neutralino-nucleon scattering (velocity-independent pieces): spin independent (scalar) spin dependent • Fraction of nucleus participates • Important for capture & annihilation rates in the sun • Whole nucleus participates • Best prospects for direct detection Fermilab Theoretical Astrophysics Seminar

  32. Neutralino-Nucleon Scattering tan = 10, Min = MGUT Fermilab Theoretical Astrophysics Seminar

  33. Neutralino-Nucleon Scattering tan = 10, Min = 1012 GeV Fermilab Theoretical Astrophysics Seminar

  34. Neutralino-Nucleon Scattering tan = 50, Min = MGUT Fermilab Theoretical Astrophysics Seminar

  35. Neutralino-Nucleon Scattering tan = 50, Min = 1014 GeV Fermilab Theoretical Astrophysics Seminar

  36. Summary/Conclusions • Relaxed the standard CMSSM assumption of universality of soft breaking parameters at the GUT scale • Examined the impact of lower Min on the constraints from colliders and cosmology • Specific attention to consequences for neutralino dark matter • In GUT-less CMSSM, constraint on dark matter abundance changes dramatically with Min • Below critical Min, neutralinos can not account for the measured relic density! Fermilab Theoretical Astrophysics Seminar

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