DARK MATTER AT THE WEAK SCALE Graciela Gelmini - UCLA TeV PA 2010 - PowerPoint PPT Presentation

DARK MATTER AT THE WEAK SCALE Graciela Gelmini - UCLA TeV PA 2010 - Paris, July 22

Graciela Gelmini-UCLA Content: • Dark Matter: what we know • WIMPs: earliest relics • New physics at the EW scale? • Burst of recent model building to account for hints of DM in Direct and Indirect searches: present hints and some models • Summary and conclusions TeV PA 2010 - Paris, July 22 1

Graciela Gelmini-UCLA Dark Matter: We know a lot! • We know its abundance in the Universe to a percent level • We know most is not baryonic • We know is it NOT explained by the Standard Model of EP TeV PA 2010 - Paris, July 22 2

Graciela Gelmini-UCLA Dark Matter: not baryons Fig: Kowalski et al 2008 2.0 No Big Bang ρ c ≃ 5 keV / cm 3 Ω = ρ/ρ c 1.5 68.3%, 95.4%, 99.7%CL constraints on Ω M and ΩΛ obtained from Cosmic Background Radiation Anisotropy CMB (orange), Baryon Acoustic Oscillations BAO (green), and the Union Compilation of 307 Type Ia supernovae (SNe Ia) (blue); Ω m = 0.285 +0 . 020 − 0 . 019 (stat) +0 . 011 1.0 − 0 . 011 (sys) assuming DE is a cosmological SNe constant WMAP7, BAO, SN1a: E. Komatsu, et al., 2010 Ω Λ = 72 . 2 ± 1 . 5% Ω m = 27 . 8 ± 1 . 5% 0.5 where Ω m is: Ω b = 4 . 61 ± 0 . 15% Ω DM = 23 . 2 ± 1 . 3% CMB Flat BAO 0.0 0.0 0.5 1.0 TeV PA 2010 - Paris, July 22 3

Graciela Gelmini-UCLA Most of the Dark Matter: is cold or warm namely is non- relativistic or semi-relativistic at galaxy formation ( T ≃ 1keV ) No CDM or WDM in the SM! (active- ν are HDM) But many in extensions of the SM! • Warm dark matter: sterile neutrino, gravitino, non-thermal WIMPs... • Cold dark matter: WIMPs (LSP or variants LKP, LZP, LTP), axion, WIMPZILLAs, solitons (Q-balls), SuperWIMPs (get their relic density from WIMPs which decay into them)... Here we concentrate on WIMPs. Why WIMP’s? The “WIMP” miracle.... TeV PA 2010 - Paris, July 22 4

Graciela Gelmini-UCLA WIMPs as Dark Matter: “Thermal WIMPs” WIMPs are the earliest relics, from the pre-BBN era of the Universe, from which we have no data! So we must make assumptions... Standard Assumptions: Universe radiation dominated at T > T f.o. ≃ m/ 20 - WIMPs reach thermal equilibrium while radiation dominates - Chemical decoupling when Γ ann = � σ annih v � n ≤ H , - No entropy change in matter + radiation Ω std h 2 ≈ 0 . 1 3 × 10 − 26 cm 3 / s � σv � Weak σ annih ≃ 3 × 10 − 26 cm 3 / s for Ω h 2 = Ω DM h 2 ∼ 0 . 1 ! TeV PA 2010 - Paris, July 22 5

Graciela Gelmini-UCLA We do not know the history of the Universe before BBN we expect to learn about it precisely from WIMPs (or sterile neutrinos..., relics from that epoch) • Earliest remnants: WIMPs decouple at T f.o. ≃ m χ / 20 • BBN (ends at t U ≃ 200 sec, T ≃ MeV) is the earliest episode from which we have a trace: the abundance of light elements D, 4 He, 7 Li. Imposes only T RH > 4 MeV (Hannestad, 2004) T RH : highest T of the radiation dominated epoch before BBN • In many viable non standard cosmological models relic densities may be very different... TeV PA 2010 - Paris, July 22 6

Graciela Gelmini-UCLA Same MSSM- non standard pre-BBN cosmology: Low T RH Models MSSM with 9 parameters + µ sign + two additional parameters T RH and η ) T RH =10 MeV T RH =100 MeV T RH =10 GeV T RH =1 GeV Same 1700 models 1e3 10 2 η = 0 0.1 Ω h (Gelmini, Gondolo, 1e-3 1e-5 Soldatenko &Yaguna, 2006) 1e3 10 η = 1e-9 All points can 2 0.1 Ω h 1e-3 be brought to 1e-5 1e3 cross the DM 10 η = 1e-6 2 0.1 Ω h cyan line with 1e-3 1e-5 suited T RH , η 1e3 10 η = 1e-3 2 Ω h 0.1 1e-3 bino-like 1e-5 1e3 higgsino-like 10 η = 1/2 2 Ω h 0.1 wino-like 1e-3 1e-5 2 3 4 2 3 4 2 3 4 2 3 4 10 10 10 10 10 10 10 10 10 10 10 10 Neutralino Mass (GeV) Neutralino Mass (GeV) Neutralino Mass (GeV) Neutralino Mass (GeV) TeV PA 2010 - Paris, July 22 7

Graciela Gelmini-UCLA New physics at the EW scale Expected because of Spontaneous Symmetry Breaking arguments (totally independently of the DM issue) Naturalness implies Λ SM ≈ O(TeV) above which the cancellation in corrections to m Higgs is due to a new theory.... • supersymmetry (with or without a composite Higgs boson) • technicolor (walking or top assisted TC) • large extra spatial dimension (possibly warped) • “Little Higgs” model (Higgs is a pseudo-Goldstone boson) which provide main potential discoveries at the LHC and “well motivated” DM candidates... mostly WIMPs: LSP, Lightest Technibaryon, LKP (Lightest KK Particle) or LZP (in Warped SO(10) with Z3 model), LTP (the Lightest T-odd heavy photon in Little Higgs with T-parity)... TeV PA 2010 - Paris, July 22 8

Graciela Gelmini-UCLA New physics to explain DM? May be different...., for example (Arkani-Hamed, Finkbeiner, Slatyer & Weiner PRD79:015014,2009) “A Theory of DM” WIMP, with 500-800 GeV mass, has an exited state with mass difference 0.1 to 1 MeV, is charged under a broken hidden gauge symmetry G dark with a boson φ lighter than 1GeV, explaining: • the DAMA signal with “inelastic” (IDM) • the INTEGRAL data with “exciting” (XDM) • the PAMELA data with WIMP’s annihilating into light φ ’s ( + ATIC, but now Fermi!) • the “WMAP Haze” ( + EGRET excess rejected by Fermi!) Attests to the ingenuity of theorists to explain everything..... Made to fit DM-not to solve the EW hierarchy.... and provides signatures for the LHC: major additions to SUSY signals, GeV-dark Higgses and gauge bosons decay into visible particles and leptons, MSSM LSP decays into the true LSP, thus many lepton jets with GeV invariant masses expected... Arkani-Hamed, Weiner JHEP0812:104,2008 TeV PA 2010 - Paris, July 22 9

Graciela Gelmini-UCLA Physics beyond the SM is required by Dark Matter, and expected at the EW scale, and both physics may or may not be related! Thus LHC and DM searches are independent and complementary. TeV PA 2010 - Paris, July 22 10

Graciela Gelmini-UCLA DM searches: Complementary to the LHC and to each other! • Direct Detection- looks for energy deposited within a detector by the DM particles in the Dark Halo of the Milky Way (Many: DAMA, XENON, CDMS, CoGent, Cresst, Edelweiss, Zeplin, LUX...) • Indirect Detection- looks for DM annihilation (or decay) products – neutrinos from Sun/Earth or the GC (AMANDA-Icecube, Antares-KM3NeT) – γ -rays and anomalous cosmic rays from Galactic Halo(s), and the Galactic Center (FST, HESS, VERITAS, PAMELA, AMS...) Many DM “hints” in both.... TeV PA 2010 - Paris, July 22 11

Graciela Gelmini-UCLA Direct DM Searches: DAMA/LIBRA 25 NaI (Tl) crystals of 9.5 kg each, 4y in LIBRA (11 years total), 0.83 ton × year, 8.2 σ modulation signal. (Bernabei et al 0804.2741) 2-4 keV DAMA/NaI (0.29 ton × yr) DAMA/LIBRA (0.53 ton × yr) Residuals (cpd/kg/keV) (target mass = 87.3 kg) (target mass = 232.8 kg) Time (day) Rate TeV PA 2010 - Paris, July 22 12

Graciela Gelmini-UCLA Direct DM Searches: New DAMA/LIBRA 25 NaI (Tl) crystals of 9.5 kg each, 6y in LIBRA (13 years total), 1.17 ton × year, 8.9 σ modulation signal. (Bernabei et al 1002.1028) 10 Rate (cpd/kg/keV) 8 6 4 2 0 2 4 6 8 10 Energy (keV) Rate TeV PA 2010 - Paris, July 22 13

Graciela Gelmini-UCLA Direct DM Searches: is the DAMA/LIBRA annual modulation signal compatible with all other searches?: maybe for light (elastically scattering) WIMP’s and inelastically scattering DM (IDM) among others... Light m < 10 GeV WIMP’s 2004: DAMA signal allowed for light WIMP m ∼ 4 − 10 GeV (SI + conventional halo) (Gelmini, Gondolo 2004, 2005) For SD too (Freese, Gondolo, Savage 2005) Here“raster scan” in m because only 2 data bins given (Example: 2-4, 6-14 keVee bins) This was then... after DAMA/LIBRA 36 data bins given TeV PA 2010 - Paris, July 22 14

Graciela Gelmini-UCLA Light m < 10 GeV WIMP’s: (e.g. Savage, Gelmini, Gondolo, Freese JCAP 0904:010,2009) 10 4 DAMA � 7 Σ � 5 Σ � 36 bins likelihood ratio 4 param. fits 10 3 DAMA � 3 Σ � 90 � � DAMA � 7 Σ � 5 Σ � 10 2 10 0 with channeling DAMA � 3 Σ � 90 � � DAMA � 7 Σ � 5 Σ � 10 1 with channeling 10 � 1 Σ Χ p � pb � DAMA � 3 Σ � 90 � � CRESST I DAMA � 7 Σ � 5 Σ � 10 0 10 � 2 with channeling TEXONO DAMA � 3 Σ � 90 � � 10 � 1 10 � 3 with channeling CoGeNT Σ Χ p � pb � CRESST I Super � K 10 � 2 10 � 4 TEXONO spin � dependent XENON 10 10 � 3 10 � 5 � a n � 0, proton only � CDMS I Si CoGeNT CDMS II Ge Super � K 10 � 4 10 � 6 10 0 10 1 10 2 10 3 XENON 10 M WIMP � GeV � spin � independent 10 � 7 CDMS I Si CDMS II Ge 10 4 10 � 8 10 0 10 1 10 2 10 3 DAMA � 7 Σ � 5 Σ � M WIMP � GeV � 10 3 DAMA � 3 Σ � 90 � � 10 2 DAMA � 7 Σ � 5 Σ � with channeling With the large channeling fraction DAMA DAMA � 3 Σ � 90 � � 10 1 with channeling Σ Χ n � pb � CRESST I 10 0 estimated, light usual WIMPs, m ≃ 7 to 10 TEXONO 10 � 1 CoGeNT 10 � 2 GeV were a possible explanation (in conflict XENON 10 spin � dependent 10 � 3 CDMS I Si � a p � 0, neutron only � CDMS II Ge with CDMS and XENON at the 2-3 σ level) 10 � 4 10 0 10 1 10 2 10 3 M WIMP � GeV � Recent revaluation of channeling: it is not important at less than 5 σ . This makes it more difficult for light WIMPs (Bozorgnia, Gelmini, Gondolo 1006.3110; Savage et al. 1006.0972) TeV PA 2010 - Paris, July 22 15