Non-WIMP Dark Matter Candidates Laura Covi Outline Introduction - PowerPoint PPT Presentation

TeV Particle Astrophysics 2010 - Paris 22.7.2010 Non-WIMP Dark Matter Candidates Laura Covi

Outline Introduction & DM (gravitational) evidence Gravitino Dark Matter & SuperWIMPs Axion Dark Matter Strongly interacting Dark Matter (?) Outlook

Introduction

DARK MATTER evidence

DARK MATTER evidence 90° 2° 0.5° 0.2° 6000 HORIZON SCALES: 5000 4000 From the position and 3000 height of the CMB 2000 anisotropy acoustic 1000 oscillations peaks 0 we can determine 10 100 500 1000 very precisely the curvature of the Universe and other background parameters.

DARK MATTER evidence 90° 2° 0.5° 0.2° 6000 CLUSTER SCALES: HORIZON 5000 SCALES 4000 3000 2000 1000 0 10 100 500 1000

DARK MATTER evidence 90° 2° 0.5° 0.2° 6000 CLUSTER SCALES: HORIZON 5000 SCALES 4000 3000 2000 1000 0 10 100 500 1000 GALACTIC SCALES

DARK MATTER evidence 90° 2° 0.5° 0.2° 6000 CLUSTER SCALES: HORIZON 5000 SCALES 4000 3000 2000 1000 0 10 100 500 1000 Ω h 2 Particles Type GALACTIC SCALES Baryons 0.0224 Cold Neutrinos < 0.01 Hot 0.1-0.13 Cold Dark Matter

Structure Formation V. Springel @MPA Munich Yoshida et al 03

Structure Formation V. Springel @MPA Munich Yoshida et al 03 CDM WDM

WDM & the Power spectrum WDM suppresses perturbations on scales smaller than its free-streaming length: � m W DM � − 1 λ F S ∼ Mpc 1keV Compare with the data: m W DM > 4 keV [Viel et al. ‘07]

All these evidences are just based on the gravitational force: either directly on the attraction of the Dark Matter on the visible matter or on the effect of the Dark Matter energy component on the Universe expansion or on the evolution of the density perturbation... So there is no doubt: DARK MATTER is gravitating ! But what about other interactions ???

DARK MATTER interaction CLUSTER SCALES: Systems like the Bullett cluster allow to restrict the self-interaction cross-section of Dark Matter to be smaller than the gas at the level σ ≤ 1 . 7 × 10 − 24 cm 2 ∼ 10 9 pb ∼ 1 barn [Markevitch et al 03] One order of magnitude stronger contraint by required a sufficiently large core... [Yoshida, Springer & White 00] Not such a strong bound...

Baryonic DARK MATTER ? Faint planets, MACHOS ? No evidence in our galaxy found by the EROS collaboration between and 20 solar masses. 10 − 7 Still clumps of non- baryonic Dark Matter, much less concentrated, may be there...

DARK MATTER lifetime? The Dark Matter keeps our galaxy together, so it should be longer lived than the Universe: τ > 10 17 s For any visible decay (photons, charged particles, even neutrinos) the limits are actually much stronger τ > 10 24 − 10 28 s Still quite far from the proton lifetime bound...

DARK MATTER properties Electrically neutral, non-baryonic, possibly electroweak interacting, but could even be only gravitationally interacting. It must still be around us: either stable or very very long lived, i.e. it is the lightest particle with a conserved charge (R-, KK-, T-parity, etc...) or its interaction and decay is strongly suppressed ! If it is a thermal relic, must be sufficiently massive to be cold..., but it may even be a condensate... LOOK FOR PARTICLE DM CANDIDATES !

DARK MATTER candidates [Roszkowski 04] (non) sneutrino KK neutrino KK DM LTP techniWIMP KK graviton

DARK MATTER candidates [Roszkowski 04] (non) sneutrino Thermal relics: KK DM WIMPs LTP techniWIMP “SuperWIMPs” Condensate Produced KK graviton gravitationally

Gravitino & SuperWIMP DM

What are SuperWIMPs ? Super/E-WIMPs are particles that are much more weakly interacting than weakly, so there is no hope of direct detection... They are usually not a thermal relic since if they are thermal their number density is compatible only with Hot/Warm DM... Moreover they do not need to have an exactly conserved quantum number to be sufficiently stable... Dark Matter may decay !!!

Classical SuperWIMPs: Gravitino or axino DM characterised by non- renormalizable interactions; Hidden photon/photino DM with interaction suppressed by a small mixing with visible U(1); Sterile/RH neutrino/FIMPs with very small Yukawa coupling; Hidden sector particles with GUT suppressed non-renormalizable interactions. ... any particle with very suppressed interaction

GRAVITINO properties: completely fixed by SUGRA ! Gravitino mass: set by the condition of ”vanishing” cosmological constant m 3 / 2 = � We K/ 2 � = � F X � SUSY scale M P It is proportional to the SUSY breaking scale and varies depending on the mediation mechanism, e.g. gauge mediation can accomodate very small � F X � giving m 3 / 2 ∼ keV, while in anomaly mediation we can even have m 3 / 2 ∼ TeV (but then it is not the LSP ...). Gravitino couplings: determined by masses, especially for a light gravitino since the dominant piece � ∂ µ ψ 2 becomes the Goldstino spin 1/2 component: ψ µ � i m 3 / 2 . Then we have: 3 1 1 1 D ν φ ∗ ¯ ¯ ψ µ σ νρ γ µ λ a F a ψ µ γ ν γ µ χ R − χ L γ µ γ ν ψ µ + h.c. √ √ − νρ − D ν φ ¯ 4 M P 2 M P 2 M P i ( m 2 φ − m 2 χ ) − m λ ψχ R φ ∗ + h.c. ¯ ¯ ψσ νρ γ µ ∂ µ λ a F a √ √ ⇒ νρ + 4 6 M P m 3 / 2 3 M P m 3 / 2 Couplings proportional to SUSY breaking masses and inversely proportional to m 3 / 2 . SUSY breaking mechanism determines which particle is the LSP and the gravitino couplings ! The gravitino gives us direct information on SUSY breaking and can be stable or unstable depending on R-parity...

Stable Gravitino

CAN the GRAVITINO be COLD Dark Matter ? YES, if the Universe was never hot enough for gravitinos to be in thermal equilibrium... Very weakly interacting particles as the gravitino are produced even in this case, at least by two mechanisms PLASMA NLSP DECAY SCATTERINGS OUT OF EQUILIBRIUM m 2 Ω 3 / 2 h 2 ∝ m 3 / 2 1 / 2 Ω NLSP h 2 Ω 3 / 2 h 2 ∝ T R m NLSP m 3 / 2

CAN the GRAVITINO be COLD Dark Matter ? YES, if the Universe was never hot enough for gravitinos to be in thermal equilibrium... Very weakly interacting particles as the gravitino are produced even in this case, at least by two mechanisms PLASMA NLSP DECAY SCATTERINGS OUT OF EQUILIBRIUM m 2 Ω 3 / 2 h 2 ∝ m 3 / 2 DANGER !!! 1 / 2 Ω NLSP h 2 Ω 3 / 2 h 2 ∝ T R ! BBN at risk ! m NLSP m 3 / 2

BBN bounds on NLSP decay Neutral relics Charged relics [Pospelov 05, Kohri & Takayama 06, [...,Kohri, Kawasaki & Moroi 04] Cyburt at al 06, Jedamzik 07,...] Excluded Need short lifetime & low abundance for NLSP Big problem for gravitino LSP with 10-100 GeV mass...

Gravitino DM summary m NLSP ∼ 100 GeV m 3 / 2 NOT LSP 1keV 1MeV 1TeV 1GeV 1eV HOT WARM COLD Excluded by LSS Th. equilibrium Not in thermal equilibrium T RH (GeV) NOT DM 10 2 10 5 10 8 10 10 τ NLSP ( s ) χ 0 1 , ˜ τ NLSP ˜ 10 − 15 10 − 3 10 − 9 10 3 10 7 Gaugino mediation Gravity mediation Gauge mediation Anomaly mediation

General neutralino NLSP [LC, Hasenkamp, Roberts & Pokorski 09] Reconsider the neutralino case in the most general terms: Compute the hadronic branching ratio exactly, including the contribution of intermediate photon, Z, Higgs and squarks.... The hadronic BR is always larger than 0.03, but for large masses it can be suppressed by interference effects...

Bino-Higgsino [LC, Hasenkamp, Roberts & Pokorski 09] EM HAD The resonant annihilation into heavy Higgses becomes much more effective ! Allows for a gravitino mass up to 10-70 GeV ! Need strong degeneracy: 2 m χ ∼ M A/H

Wino-Higgsino [LC, Hasenkamp, Roberts & Pokorski 09] The Wino case has even stronger annihilation and lower energy density; apart for the resonance region, also a light Wino can allow for 1-5 GeV gravitino masses...

Degenerate gauginos NLSP [LC, Olechowski, Pokorski, Turzynski,Wells ....] 0.0001 0.001 0.01 0.1 1 10. 10. 10. M NLSP = 300 GeV bino NLSP Gluinos annihilate most efficiently, but are a 1 1 bad NLSP due to 0.1 0.1 BBN bound state � NLSP h 2 � NLSP h 2 ranges effects... allowed by BBN 0.01 0.01 T R � 2 � 10 9 GeV T R � 5 � 10 8 GeV wino NLSP On the other hand they w � o Sommerfeld eff. 0.001 0.001 with Sommerfeld eff. can help the other neutralinos NLSP. bino � wino bino bino � wino bino wino 0.0001 0.0001 0.0001 0.001 0.01 0.1 1 10. m g � � m NLSP � 1 The coannihilation with gluinos has a very strong effect on the Bino, even for just 10% degeneracy. Less effect for Wino.

Degenerate gauginos NLSP [LC, Olechowski, Pokorski, Turzynski,Wells ....] 200 400 600 800 1000 200 400 600 800 1000 10 10 10 10 100. 100. 10 9 10 9 � � g � degen. � � degen. � 10. 10. 1 � B 1 � 2 � 1 � 1 � B � g 10 8 10 8 m 3 � 2 � GeV � T R � GeV � � � degen. � � degen. � � g 1 � 2 � 1 � 10 � B � g 10 � B 10 7 10 7 1. 1. 10 6 10 6 1 � 2 � 1 0.1 � � g � degeneracy 0.1 no B 10 5 10 5 universal bino NLSP bino NLSP 0.01 0.01 10 4 10 4 200 400 600 800 1000 200 400 600 800 1000 � � GeV � m m � � GeV � B B The coannihilation with gluinos allows to reach gravitino masses in the 10 GeV range (high T_R), but with very strong degeneracy...