Dark Matter. Pearl Sandick. the University of Texas at Austin

Transcription

1 SUSY SUSY Dark Dark Matter Matter (updates (updates and and asides) asides) Pearl Sandick the University of Texas at Austin

2 Dark Dark Matter Matter WMAP ΩDM= ± It's non-baryonic (BBN+CMB, structure formation). It's stable or very long-lived. It's not charged (heavy isotope abundances). It's largely non-relativistic (cold). Komatsu et al. (2009) 85% of the matter density of the universe is unexplained by the Standard Model. Kowalski et al. (2008)

3 Plan Plan SUSY Dark Matter (WIMPs and WIMPier) How to find it Who's looking

4 SUSY SUSY Dark Dark Matter Matter The LSP may be an excellent dark matter candidate The lightest one may be stable (WIMP?) with Ωχh2 ΩDMh2 The lightest SUSY particle (LSP) is stable if R-parity is conserved. R = (-1)3 B + L +=2 S +1 for SM particles -1 for sparticles 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

5 Why Why SUSY? SUSY? Aesthetically neat extension Stabilizes the Higgs vev (Hierarchy Problem) Gauge coupling unification Predicts a light Higgs boson Just right! mh2 log(λ UV ) (< < mh2 )

6 MSSM MSSM Also axion: a, spin 0 saxion: s, spin 0 ~ spin ½ axino: a, graviton: G, spin 2 ~ spin 3/2 gravitino: G, quarks and squarks leptons and sleptons W boson and wino gluon and gluino B boson and bino Higgs bosons and higgsinos

7 SuperWIMPs SuperWIMPs (E-WIMPs) (E-WIMPs) Interaction scale with ordinary matter suppressed by large mass scale: For gravitino, mp 1019 GeV (gravitational interactions) For axino, fa 1011 GeV σ (mw/ fa)2 σweak σweak pb Choi & Roszkowski (2005)

8 Axinos Axinos Axion is a solution to the strong CP problem, i.e. Why does QCD conserve CP when CP violating operators are allowed? Peccei-Quinn Mechanism: Promote CP-violating operator to a field by requiring new global (P-Q) symmetry P-Q symmetry is spontaneously broken Axion is Goldstone Boson ( pseudo due to small mass from QCD vacuum effects) SUSY: axion is in a chiral multiplet with axion + saxion, axino: Axion gets its mass from QCD effects: SUSY breaking splits saxion/axino masses from tiny axion mass ms~ msusy (not LSP) m~a unconstrained (could be LSP and DM)

9 Axino Axino Dark Dark Matter Matter If the axino is the LSP, expect non-thermally produced axinos from neutralino NLSP decay see Baer et al. (2010) and references therein axions from vacuum mis-algnment mechanism thermally produced axinos from radiation off MSSM scattering processes TP axinos are CDM for

10 Gravitino Gravitino Dark Dark Matter Matter Like axino, both thermal and non-thermal production mechanisms NTP: Late decays of NLSP can lead to entropy overproduction and hot dark matter, so mnlsp > 500 GeV ΩGh2 ~ 0.1 for 1 GeV < mg < 700 GeV (Steffen, 2006) TP: TR << Tf to avoid overproduction of gravitinos ( Gravitino Problem ) For natural ranges of gluino and gravitino masses, one can have TP ΩGh2 ~ 0.1 at TR as high as GeV. NLSP decays produce energetic SM particles, could spoil BBN light element abundances

11 Gravitino Gravitino Mass Mass Gravitino mass depends on how SUSY breaking is communicated to the observable sector: Gravity (modulus) mediated SUSY: m3 / GeV few TeV Anomaly mediated SUSY: m3 / 2 10 TeV 100 TeV Gauge mediated SUSY: m3 / 2 10 ev 1 GeV Gaugino mediated SUSY: m3 / 2 10 GeV TeV maybe LSP not LSP probably LSP maybe LSP

12 WIMP WIMP Dark Dark Matter Matter Expansion and annihilation compete to determine the number density: Stable matter with GeV-TeV mass and weak-scale interaction strength yield Ωh2 ~ 0.1 Jungman, Kamionkowski and Griest, PR 1996

13 Sneutrinos Sneutrinos L-handed neutrinos have L-handed sneutrino superpartners in the MSSM Large coupling to Z boson leads to low relic abundance and larger-than-observed scattering rates with nuclei. Falk, Olive & Srednicki (1994) Low mass window closed by limits from invisible Z decay at LEP. LEPEWWG (2003) R-handed neutrinos can be added to the SM to explain the origin of neutrino masses, so expect R-handed sneutrino partners. L-R mixed sneutrinos have reduced coupling to Z, but a significant L-R mixing is only possible in very particular SUSY-breaking scenarios. Pure R-handed sneutrinos could be CDM, but can't be thermal relics because their coupling to ordinary matter is very small. These ARE viable DM candidates in SUSY models with extended gauge or Higgs sectors (and therefore additional matter interactions). Arina & Fornengo (2007), Asaka, Ishiwata & Moroi (2007), Cerdeno & Seto (2009), etc.

14 Sneutrinos Sneutrinos Example: MSSM + gauged U(1)B-L Allahverdi et al. (2007, 2009) DM could be R-sneutrino if U(1)B-L is broken at ~TeV scale. Example: MSSM + singlet superfield S for μ problem + singlet superfield N for R-(s)neutrino states Cerdeno & Seto (2009) DM is pure R-sneutrino with couplings to MSSM fields, so it has the properties of a thermally-produced WIMP. Example: MSSM + 6 complex sneutrino fields (12 mixed L/R sneutrino mass eigenstates) March-Russell, McCabe & McCullough (2009) DM could be lightest sneutrino, or combination of long-lived sneutrinos Bottom line: Sneutrino DM must be substantially R-handed to suppress coupling to Z, so generally arises in extended versions of the MSSM. Properties of sneutrino depend on the MSSM extension many possibilities.

15 Neutralinos Neutralinos The LSP is a neutralino in much of parameter space of even most-constrained SUSY models. The lightest one may be a stable WIMP with Ωχh2 ΩDMh2 Properties of neutralino LSP depend on its composition.

16 Dark Dark Matter Matter Detection Detection Colliders Produce Dark Matter directly (missing energy signature) Observe decays of NLSPs Direct Detection Observe WIMPs through interactions with matter in terrestrial detectors (axions?) Indirect Detection Observe products of WIMP annihilation/decay in terrestrial or space-based detectors

17 Plan Here Plan From From Here Direct Detection, current status, what it means for SUSY, and tensions Indirect Detection, current status, what it means for SUSY, and other possibilities LHC/ILC dark matter connection

18 Direct Direct Detection Detection Case Case Study Study CMSSM: GUT-scale universality Scalar masses Gaugino masses Trilinear couplings tan(beta) sign(mu) spin dependent (axial vector) Fraction of nucleus participates Important for capture & annihilation rates in the sun spin independent (scalar) Whole nucleus participates Best prospects for direct detection

19 CMSSM CMSSM Ellis, Olive, Sandick (2009) Focus Point Coannihilation Strip

20 CMSSM CMSSM Ellis, Olive, Sandick (2009) XENON10 CDMS II SuperCDMS XENON100

21 Departures Departures from from CMSSM CMSSM More general patterns of SUSY breaking: NU scalar masses m0 FCNC suppression suggests universality of matter fields that share quantum numbers NU gaugino masses M1/2 SUSY GUTs: varying degrees of universality SO(10): mh, m0, M1/2 SU(5): some masses equal NU trilinear couplings A0 msugra: m0 (also for Higgses), M1/2 NU Higgs masses? Extended particle content NMSSM nmssm UMSSM extra singlet superfield mirage mediation: universality below the GUT scale (GUT-less SUSY) some string scenarios for SUSY breaking: maybe no universality at any scale! etc.

22 NUHM NUHM Ellis, Olive, Sandick (2009) NUHM1 CMSSM

23 Direct Direct Searches Searches Searches Signals... (+ example of SUSY modelbuilding to accommodate them) Current limits, projected sensitivities

24 Strategies & Searches Strategies & Searches One-channel Ionization: GENIUS, IGEX, HDMS, TEXONO, CoGeNT Scintillation: DAMA, NAID, DEAP, CLEAN, XMASS, KIMS Phonons: CUORE, CRESST-I Bubble Chambers: PICASSO, COUPP Two-channel (better BG discrimination) I+P: EDELWEISS, EUREKA, CDMS, SuperCDMS I+S: ArDM, ZEPLIN, WARP, XENON, LUX S+P: CRESST-II

25 SD SD Status Status χ-n χ-p

26 SI SI Status Status (~1 (~1 year year ago) ago) CoGeNT Collaboration (2010) CDMS-II (2 events) DAMA CoGeNT exclusion CoGeNT signal CMSSM (shaded)

27 CoGeNT CoGeNT

28 SI SI Status Status (~1 (~1 year year ago) ago) CoGeNT Collaboration (2010) CDMS-II (2 events) DAMA CoGeNT exclusion CoGeNT signal CMSSM (shaded)

29 Is Is it it MSSM? MSSM? No. Feldman et al. (2010) NMSSM? Also no. (though maybe with a generic extra chiral singlet superfield)

30 Possible Possible Resolution Resolution CDMS II (2010) DAMA/LIBRA CoGeNT CDMS II 2 kev (solid) CDMS II 10 kev (dot-dashed) XENON100 XENON10 CRESST

31 Looking Looking Forward Forward Projected sensitivity to MOST SUSY WIMP dark matter models. If it's not a WIMP, wrong tree... If these techniques don't find it...? -> Need directional detection: DMTPC (irreducible neutrino background)

32 Indirect Indirect Searches Searches What to look, where to look for it Recent excitement (+ SUSY modelbuilding response)

33 Indirect Indirect Searches Searches Satellites Galactic Center Milky Way Halo Annihilation in our Sun/Earth (capture) Spectral Lines (small BR) Extra-Galactic (galactic background)

34 Final State Final State Bertin et al. 2002

35 Indirect Indirect Searches Searches photons γ-rays: Fermi, VERITAS, MAGIC, HESS... Microwave (synchrotron): WMAP, Planck neutrinos Super-Kamiokande, IceCube, KM3NeT electrons/positrons, protons/antiprotons Fermi, PAMELA, AMS...

36 positrons positrons PAMELA positron fraction: Adriani et al Fermi electron + positron flux: Ackermann et al. 2011

37 SUSY SUSY model-building model-building non-thermal wino dark matter (Kane et al.) no direct detection signals, due to ~100% wino content requires substantial tuning of the propagation model nearby [neutralino] dark matter clumps (Hooper et al.) maybe signals indicate substructure? TeV-scale boosted leptophilic dark matter in SUSY extensions e.g. gauged U(1)B-L: lightest neutralino in the B-L sector, or RH sneutrino (Allahverdi, Dutta et al.) B-L neutralinos -> 2 B-L Higgses (~10 GeV, decay to fermions) Sommerfeld enhancement, SI scattering (>~ pb), no SD, possible LHC, gamma-rays in FGST... RH sneutrino, same dominant annihilation mode Sommerfeld, SI scattering ( pb), no SD, but leptonic ann. -> neutrinos from the Sun detectable, LHC, gamma-rays

38 AMS-02 AMS-02 Launch ~19 April, 2011 Proton rejection of 10-6!! (for Ee+ < 300 GeV) PAMELA claims 10-5, though some are skeptical...

39 Neutrinos Neutrinos Sandick et al. (2010) IceCube discovery reach (10 yrs.) Mandal et al. (2010)

40 Neutrinos Neutrinos from from the the Sun Sun Ellis et al. (2010)

41 Gamma-Rays Gamma-Rays Abdo et al. (2010)

42 Gamma-Rays Gamma-Rays Fermi-LAT Collaboration (2010) Baltz et al. JCAP 0807, 2008

43 Colliders Colliders Status from LHC (haven't found SUSY or Dark Matter) What the LHC can find: new weak-scale physics Follow-up measurements with a linear collider... Need DD or LC to prove dark matter

44 SuperWIMP SuperWIMP Dark Dark Matter Matter Unfortunately, no [traditional] direct or indirect WIMP detection signals are expected for stable axino/gravitino dark matter. If R-parity is broken, decaying axinos/gravitinos may be responsible for the PAMELA positron excess. Depending on R-parity breaking model, radiative or leptonic decay channels may be preferred. Collider signatures are possible, but depend on NLSP: Charged NLSP would be easy to see, but would need to carefully study its decays to determine what the LSP is. Decays would likely happen outside the detector (need to trap sleptons) Neutral NLSP would be harder to see, and could itself be dark matter. Mass and couplings compatible? see, for example, Covi et al. (2001), Covi & Kim (2009)

45 Gravitino Gravitino vs. vs. Axino Axino Can we tell them apart? Maybe! If long-lived staus are accumulated and observed, we might be able to determine if CDM is axino or gravitino based on stau decay event distributions. Brandenburg et al. (2005)

46 Summary Summary Direct Detection: Hints, but probably not dark matter Increase in sensitivity is promising (news before 2012?) Indirect Detection: Hints, but probably not dark matter AMS will help unravel mystery Coincident signals would be great; need to show (at least) that dark matter is the BEST explanation, not just a possible explanation Colliders: [discuss]

47 EXTRA EXTRA SLIDES SLIDES

48 SUSY SUSY DM DM Candidates Candidates A plethora of DM candidates: neutralinos (our favorite WIMPs) H. Goldberg, Phys. Rev. Lett. 50, 1419 (1983); J. Ellis, J. Hagelin, D.V. Nanopoulos, K. Olive, and M. Srednicki, Nucl. Phys. B 238, 453 (1984), etc. sneutrinos (also WIMPs) T. Falk, K. A. Olive and M. Srednicki, Phys. Lett. B 339 (1994) 238; T. Asaka, K. Ishiwata, and T. Moroi, Phys. Rev. D 73, (2006); 75, (2007); F. Deppisch and A. Pilaftsis, J. High Energy Phys. 10 (2008) 080; J. McDonald, J. Cosmol. Astropart. Phys. 01 (2007) 001; H. S. Lee, K. T. Matchev, and S. Nasri, Phys. Rev. D 76, (2007); D. G. Cerdeno, C. Munoz, and O. Seto, Phys. Rev. D 79, (2009); D. G. Cerdeno and O. Seto, J. Cosmol. Astropart. Phys. 08 (2009) 032; etc. gravitinos (SuperWIMPs) J.L. Feng, A. Rajaraman and F. Takayama, Phys. Rev. Lett. 91, (2003) [hep-ph/ ], Phys. Rev. D 68, (2003) [hep-ph/ ]; J.R. Ellis, K.A. Olive, Y. Santoso and V.C. Spanos, Phys. Lett. B 588, 7 (2004) [hep-ph/ ]; J.L. Feng, S.f. Su and F. Takayama, Phys. Rev. D 70, (2004) [hep-ph/ ]; etc. axinos (SuperWIMPs) T. Goto and M. Yamaguchi, Phys. Lett. B 276, 103 (1992); L. Covi, H.B. Kim, J.E. Kim and L. Roszkowski, JHEP 0105, 033 (2001) [hep-ph/ ]; L. Covi, L. Roszkowski, R. Ruiz de Austri and M. Small, JHEP 0406, 003 (2004) [hep-ph/ ]; etc.

49 WIMP WIMP Miracle Miracle 1. New (heavy) particle χ in thermal equilibrium: χχ 1 2 ff 2. Universe expands and cools: χχ 3 ff 3. χ's freeze out χχ ff Jungman, Kamionkowski and Griest, PR 1996

50 Why Why SUSY? SUSY? Aesthetically neat extension R. Haag, J. T. Lopuszanski and M. Sohnius Nucl. Phys. B 88 (1975) 257 Extended the Poincare algebra: Q boson> = fermion> and Q fermion> = boson> Find a consistent theory with interplay of Poincaré and internal symmetries. Supersymmetry is the only nontrivial extension of the Pioncaré algebra in a consistent 4-d QFT.

51 Why Why SUSY? SUSY? Aesthetically neat extension Stabilizes the Higgs vev (Hierarchy Problem) SM: 2 V = mh2 2 + λ 4 λf 2 2 m = Λ From W and Z masses, know < >=174 GeV, H UV π so expect mh2 ~ (100 GeV)2 SUSY: mh2 log(λ UV ) < < mh2 SUSY maintains hierarchy of mass scales.

52 Why Why SUSY? SUSY? Aesthetically neat extension Stabilizes the Higgs vev (Hierarchy Problem) Gauge coupling unification Near miss! Just right! Running (b s) depends only on particle content of the model.

53 Why Why SUSY? SUSY? Aesthetically neat extension Stabilizes the Higgs vev (Hierarchy Problem) Gauge coupling unification Predicts a light Higgs boson MSSM: 105 GeV < < 135 GeV ~ mh ~ LEP: GeV < m h < 157 GeV LEP Collaborations and Electroweak Working Group, August 2009

54 MSSM MSSM MSSM: Minimal Supersymmetric Standard Model Has the minimal particle content possible in a SUSY theory.

55 SUSY SUSY Breaking Breaking (pheno.) (pheno.) Don t observe boson-fermion degeneracy, so SUSY must be broken (How?) Most general case (MSSM) has > 100 new parameters! OR 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 Example: CMSSM (similar to msugra) Assume universality of soft SUSY-breaking parameters at M GUT Free Parameters: m0, m1/2, A0, tan(β), sign(μ)

56 Constraints Constraints Apply constraints from colliders and cosmology: mh > 114 GeV mχ± > 104 GeV LEP BR(b s γ) HFAG BR(Bs µ+µ--) CDF (gµ - 2)/2 g-2 collab Ωχh2 0.12

57 CMSSM CMSSM LEP Higgs mass Relaxed LEP Higgs µ2 < 0 (no EWSB) LEP chargino mass gµ-2 suggested region stau LSP Ellis, Olive, Sandick (2006)

58 CMSSM CMSSM b sγ B μ+μ-- Ellis, Olive, Sandick (2006)

59 CMSSM CMSSM Focus Point LEP Higgs mass Relaxed LEP Higgs µ2 < 0 (no EWSB) LEP chargino mass gµ-2 suggested region Coannihilation Strip stau LSP Ellis, Olive, Sandick (2006)

60 Axino Axino Dark Dark Matter Matter Covi et al. (2004); Choi and Roszkowski (2005)

61 Gravitino Gravitino Dark Dark Matter Matter Neutrino signals? Only if gravitino is unstable... (RPV) NLSP decays to SM particles quickly Gravitinos TP at reheating Long-lived, ~150 GeV gravitinos decay, contributing to the CR positron excess and the diffuse gamma-ray flux Covi et al. (2009)

62 CMSSM CMSSM Rapid annihilation funnel 2mχ ma b sγ B μ+μ-- Ellis, Olive, Sandick (2006)

63 Departures Departures from from CMSSM CMSSM More general patterns of SUSY breaking: NU scalar masses m0 FCNC suppression suggests universality of matter fields that share quantum numbers NU gaugino masses M1/2 SUSY GUTs: varying degrees of universality SO(10): mh, m0, M1/2 SU(5): some masses equal NU trilinear couplings A0 msugra: m0 (also for Higgses), M1/2 NU Higgs masses? Extended particle content NMSSM nmssm UMSSM extra singlet superfield mirage mediation: universality below the GUT scale (GUT-less SUSY) some string scenarios for SUSY breaking: maybe no universality at any scale! etc.

64 NUHM NUHM CMSSM Higgs masses determined by NUHM1 One extra free parameter: NUHM2 No constraint at GUT scale CMSSM GUT-scale inputs: Use electroweak vacuum conditions:

65 Indirect Indirect Detection Detection s-wave zero relative velocity Bino: heavy fermions [down-type favored for large-ish tan(β)], WW Wino: gauge bosons Higgsino: gauge bosons Example: Coannihilation Strip (mostly bino, 321 GeV) ~39% taus, ~27% WW, ~17% bb, ~15% tt Example: Focus Point (bino-higgsino mix, 140 GeV) ~94% WW, ~5% ZZ, ~1% hz

66 Closing Closing Remarks Remarks The identification of dark matter is a very interesting problem. Supersymmetry is an attractive theory in which there are several possible dark matter candidates. SuperWIMPs: Axino and Gravitino WIMPs: Sneutrino and Neutralino Dark matter phenomenology depends on many assumptions about SUSY breaking, but some general conclusions can be drawn (especially for MSSM neutralino dark matter). We hope for agreement among many experiments and techniques (direct detection, indirect detection, and collider experiments) to give us a consistent picture of dark matter and its properties.