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Nachweismethoden der DM

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1 Nachweismethoden der DM
Gravitationslinsen Rotationskurven Indirekter Nachweis der DM ( Annihilation der DM in Materie-Antimaterie) Direkter Nachweis der DM ( Elastische Streuung an Kernen)

2 Gravitationslinsen ART: Die Ausbreitung von Licht ändert sich
beim Durchgang durch ein Gravitationsfeld

3 Gravitationslinsen

4 Colliding Clusters Shed Light on Dark Matter
Blau: dunkle Materie aus Gravitations- potential dunkel Rot: sichtbares Gas Observations with bullet cluster: Chandra X-ray telescope shows distribution of hot gas Hubble Space Telescope and others show distribution of dark matter from weak gravitational lensing Distributions are clearly different after collision-> dark matter is weakly interacting!

5 Simulation der “Colliding Clusters”
August 22, 2006

6 Discovery of DM in 1933 Zwicky, Fritz (1898-1974
Center of the Coma Cluster by Hubble space telescope ©Dubinski Zwicky notes in 1933 that outlying galaxies in Coma cluster moving much faster than mass calculated for the visible galaxies would indicate DM attracts galaxies with more force-> higher speed. But still bound!

7 Dunkle Materie im Universum
Die Rotationskurven von Spiralgalaxien sind weitgehend flach, während die leuchtende Materie eine abfallende Kurve erwarten lässt. Erklärung: dunkle Materie. Spiralgalaxien bestehen aus einem zentralen Klumpen und einer sehr dünnen Scheibe leuchtender Materie, welche von einem nahezu sphährischen, sehr ausgedehnten Halo umgeben ist.

8 Messung der Masse durch Newtons Gravitationsgesetz
v=ωr v1/r mv2/r=GmM/r2 Milchstraße Cygnus Perseus Orion Sagittarius Scutum Crux Norma Sun (8 kpc from center)

9 Do we have Dark Matter in our Galaxy?
Rotationcurve Solarsystem rotation curve Milky Way 1/r

10 Estimate of DM density DM density falls off like 1/r2 for v=const.
Averaged DM density “1 WIMP/coffee cup” (for 100 GeV WIMP)

11 Virialsatz Für Ensemble wechselwirkender Systeme im mechanischen Gleichgewicht gilt Für N Teilchen, also N(N-1)/2 Teilchenpaaren Für N groß: und Erwarte also für ´Gas` gravitativ wechselwirkender Teilchen M  r ! Aber dann: vrot2M/r = konst -> flache Rotationskurve

12 Expansion rate of universe determines WIMP annihilation cross section
T>>M: f+f->M+M; M+M->f+f T<M: M+M->f+f T=M/22: M decoupled, stable density (wenn Annihilationrate  Expansions- rate, i.e. =<v>n(xfr)  H(xfr) !) Thermal equilibrium abundance Actual abundance Comoving number density WMAP -> h2=0.113 > <v>= cm3/s DM increases in Galaxies: 1 WIMP/coffee cup 105 <ρ>. DMA (ρ2) restarts again.. Annihilation into lighter particles, like quarks and leptons -> 0’s -> Gammas! T=M/22 10-9s Only assumption in this analysis: WIMP = THERMAL RELIC! x=m/T Gary Steigmann/ Jungmann et al.

13 What is known about Dark Matter?
95% of the energy of the Universe is non-baryonic 23% in the form of Cold Dark Matter Dark Matter enhanced in Galaxies and Clusters of Galaxies but DM widely distributed in halo-> DM must consist of weakly interacting and massive particles -> WIMP’s Annihilation with <σv>= cm3/s, if thermal relic From CMB + SN1a + surveys If it is not dark It does not matter DM halo profile of galaxy cluster from weak lensing

14 Kandidaten der DM † † ? ? Problem: max. 4% der Gesamtenergie
des Univ. in Baryonen nach CMB und BBN. Sichtbar nur 0.5%, d.h. 3.5% in obigen Kandidaten möglich. Rest der DM muss aus nicht-baryonischen Materie bestehen. Probleme: ν < 0.7% aus WMAP Daten kombiniert mit Dichtekorrelationen der Galaxien. Für kosmische Strings keine Vorhersagekraft. Abweichungen von Newtons Gravitationsgesetz nicht plausibel. WIMPS ergeben nach Virialtheorem flache Rotationskurven. In Supersymmetrie sind die WIMPS Supersymmetrische Partner der CMB d.h. Spin ½ Photonen (Photinos genannt).

15 p+e <->H electromagnetic x-section
Simple 3-Component Galaxy: p+e+Wimps Interactions: p+e <->H electromagnetic x-section p+p -> X strong x-section: cm2 p+W -> p+W x-section:<10-43 cm2 (direct DM searches) W+W -> X x-section: cm2 (Hubble expansion) These cross sections are exactly order of magnitude predicted by SUSY!

16 Example of DM annihilation (SUSY)
f Z W  0 ~ A ≈37 gammas Dominant  +   A  b bbar quark pair Sum of diagrams should yield <σv>= cm3/s to get correct relic density Quark fragmentation known! Hence spectra of positrons, gammas and antiprotons known! Relative amount of ,p,e+ known as well.

17 Annihilation products from dark matter annihilation: Gamma rays
Indirect Dark Matter Searches in the Light of ATIC, FERMI, EGRET and PAMELA Annihilation products from dark matter annihilation: Gamma rays (EGRET, FERMI) Positrons (PAMELA) Antiprotons (PAMELA) e+ + e- (ATIC, FERMI, HESS, PAMELA) Neutrinos (Icecube, no results yet) e-, p drown in cosmic rays?

18 Conclusion sofar IF DM particles are thermal relics from early universe they can annihilate with cross section as large as <v>= cm3/s which implies an enormous rate of gamma rays from π0 decays (produced in quark fragmentation) (Galaxy=1040 higher rate than any accelerator) Expect significant fraction of energetic Galactic gamma rays to come from DMA in this case. Remaining ones from pCR+pGAS-> π0+X , π0->2γ (+some IC+brems) This means: Galactic gamma rays have 2 components with a shape KNOWN from the 2 BEST studied reactions in accelerators: background known from fixed target exp. DMA known from e+e- annihilation (LEP)

19 Anmerkungen zur indirekten Suche nach DM
Gamma rays: keine Ablenkung durch das Galaktische Magnetfeld zeigen daher in Richtung der Quelle kaum Abschwächung in der Galaxie bei GeV Photonen Astrophysikalische Quellen als Punktquellen erkennbar und können daher subtrahiert werden Untergrund hat anderes (aber bekanntes) Spektrum als DMA Signal. Durch gleichzeitiges Fitten von Form des Spektrums für Signal und Untergrund können beide Beiträge direkt aus den Daten bestimmt werden, wenn man die Normierung als freier Fitparameter behandelt (data driven analysis) Geladene Teilchen: Ablenkung durch das Galaktische Magnetfeld, sie zeigen daher nicht in Richtung der Quelle Wahrscheinlichkeit, dass z.B. Antiproton aus DMA im Detektor ankommt, stark abhängig vom Propagationsmodell Keine Trennung von astrophysikalischen Punktquellen möglich

20 man Untergrund? Woher erwartet
Quarks from WIMPS in protons Background from nuclear interactions (mainly p+p-> π0 + X ->  + X inverse Compton scattering (e-+  -> e- + ) Bremsstrahlung (e- + N -> e- +  + N) Shape of background KNOWN if Cosmic Ray spectra of p and e- known

21 Energy loss times of electrons and nuclei
= 1/E dE/dt univ Protons diffuse for long times without loosing energy! If centre would have harder spectrum, then hard to explain why excess in outer galaxy has SAME shape (can be fitted with same WIMP mass!)

22 Usual astrophysicist’s search strategies
Particle physicist: get rid of model dependence by DATA DRIVEN calibration

23 EGRET on CGRO (Compton Gamma Ray Observ
EGRET on CGRO (Compton Gamma Ray Observ.) Data publicly available from NASA archive Instrumental parameters: Energy range: GeV Energy resolution: ~20% Effective area: 1500 cm2 Angular resol.: <0.50 Data taking: Main results: Catalogue of point sources Excess in diffuse gamma rays

24 Two results from EGRET paper Enhancement in ringlike
Called “Cosmic enhancement Factor” Excess Enhancement in ringlike structure at kpc 1 10 Eγ GeV

25 Untergrund + DM Annihilation beschreiben Daten
W. de Boer et al., 2005

26 Analyse der EGRET Daten in 6 Himmelsrichtungen
A: inner Galaxy C: outer Galaxy B: outer disc Total 2 for all regions :28/36  Prob.= 0.8 Excess above background > 10σ. D: low latitude E: intermediate lat. F: galactic poles A: inner Galaxy (l=±300, |b|<50) B: Galactic plane avoiding A C: Outer Galaxy D: low latitude (10-200) E: intermediate lat. (20-600) F: Galactic poles (60-900)

27 EGRET Excess predicts shape of rotation curve!
Outer Ring Inner Ring bulge totalDM 1/r2 halo disk Rotation Curve Normalize to solar velocity of 220 km/s R0=8.3 kpc R0=7.0 v R/R0 Inner rotation curve Outer RC Black hole at centre: R0=8.00.4 kpc Sofue &Honma Note 1: Absolute value of rotation curve depends on distances. But chance of slope can ONLY be explained by ringlike structure. Note 2: fact that shape of DM halo can describe shape of RC implies that EGRET excess has exactly right intensity to deliver grav. potential!

28 Gas flaring in the Milky Way
no ring with ring P M W Kalberla, L Dedes, J Kerp and U Haud, Gas flaring needs EGRET ring with mass of M☉!

29 Inner Ring coincides with ring of dust and H2 ->
gravitational potential well! H2 4 kpc coincides with ring of neutral hydrogen molecules! H+H->H2 in presence of dust-> grav. potential well at 4-5 kpc. Enhancement of inner (outer) ring over 1/r2 profile 6 (8). Mass in rings 0.3 (3)% of total DM

30 FERMI measures GeV gamma rays + electrons


32 Diffuse gamma rays from FERMI
Published FERMI data on VELA pulsar: agrees within errors with EGRET at 3 GEV astro-ph/ 20% EGRET 100% Why diffuse spectrum disagrees 100% with EGRET at 3 GeV while VELA spectrum agrees with EGRET at 3 GeV within 20%?

33 Indirect Dark Matter Searches using charged particles
Annihilation products from dark matter annihilation: Gamma rays (EGRET, FERMI) Positrons (PAMELA) Antiprotons (PAMELA) e+ + e- (ATIC, FERMI, HESS, PAMELA) Neutrinos (Icecube, no results yet) e-, p drown in cosmic rays?

34 The PAMELA Satellite Experiment (launched July 2006)
Resurs Dk1 Satellite Transition Radiation Detector (removed for tech.reasons) Time of Flight Counters Silicon Tracker and Permanent Magnet Si-W Electromagnetic Calorimeter Neutron Detector Anticoincidence Shield 1.2 m 20.5 cm2sr ~450 kg ~10 T Bottom Scintillator km

35 PAMELA, positron and antiproton measurements
Positron fraction Antiproton/proton ratio Galprop Pamela Nature 458:60,2009,arXiv: (O. Adriani et. al., PRL (2009)[ ]) +prelim. new data, Boezio, Pamela-WS 2009 Positrons: excess Antiprotons: NO excess

36 ATIC Balloon experiment, Nature 2008
Kaluza-Klein DM decays to lepton pairs ->peak in electron spectrum with tail from energy losses KK x-section  Y4 so mainly decay to leptons and u-quarks Baltz, Hooper, hep-ph/ Hooper, Zurek,

37 FERMI electron spectrum: NO BUMP at 600 GeV
Simulating the LAT response to a spectrum with an “ATIC-like” feature: Alexander Moiseev Pamela workshop May 11, 2009 This demonstrates that the Fermi LAT would have been able to reveal “ATIC-like” spectral feature with high confidence if it were there. Energy resolution is not an issue with such a wide feature

38 Cherenkov telescopes measure TeV gamma rays

39 HESS, May 2009 Electron spectrum falls off above 1 TeV

40 Interpretations for charged particle anomalies
Many possibilities: Background from hadronic showers with large electromagnetic component -> ap->0 astrophysical sources pulsars -> apulsar positron acceleration in SNR -> asec locality of sources -> aSNR dark matter annihilation -> aDMA leptophilic? bound states? Kaluza-Klein

41 Truth? Unitarity must be fulfilled. However, will now
Depends on whom you ask! My assumption: |Data>= ap->0 |Background> + aDMA |DMA> + asec |SNR> + alocal |SNR(x)> + apulsar |Pulsar> Unitarity must be fulfilled. However, will now show that each component has enough uncertainty to saturate observations

42 aDMA:DM interpretation of FERMI e-data
TeV DM decaying to low scale particle, which can only decay leptonically TeV DM forms bound state to get large boost factor via Sommerfeld enhancement Models e.g. by Arkani-Hamed,Finkbeiner,Slatyer,Weiner arXiv: Nomura and Thaler, arXiv: Fit by Bergstrom et al.arXiv:

43 e loose energy rapidly (dE/dt  E2), hence they are “local”
aloc :3-component e- sources: spiral arm, disc, local Shaviv et al., arXiv: ,2009 spiral arm near sources positrons disc e loose energy rapidly (dE/dt  E2), hence they are “local” 3-component structure explains e-spectrum, Pamela/Fermi anomalies and why nothing in pbar It can work!

44 What about Supersymmetry? Assume mSUGRA
5 parameters: m0, m1/2, tanb, A, sign μ

45 Example of DM annihilation (SUSY)
f Z W  0 ~ A ≈37 gammas Dominant  +   A  b bbar quark pair Sum of diagrams should yield <σv>= cm3/s to get correct relic density Quark fragmentation known! Hence spectra of positrons, gammas and antiprotons known! Relative amount of ,p,e+ known as well.

46 Expected SUSY mass spectra in mSUGRA for EGRET WIMP mass of 60 GeV
mSUGRA: common masses m0 and m1/2 for spin 0 and spin ½ particles

47 Annihilation cross sections in m0-m1/2 plane (μ > 0, A0=0)
tan=5 tan=50 t t 10-27 bb t t 10-24 bb EGRET WMAP  WW  WW For WMAP x-section of <v> cm3/s one needs large tanβ

48 Mt/Mb = tan  Mt2=(4)2Yt v22 Mb2=(4)2Yb v12



51 EWSB requirement leads to small MA at large tan ß
m12 Yb tan ß = 20 tan ß = 51 m12 Yb m22 Yt m22 Yt EWSB: MZ2/2=(m12-m22 tan2ß)/ (tan2ß-1) -m22 for large tan ß Pseudoscalar Higgs: MA2 = m12+m22 becomes very small if YtYb at large tb (Mt2/Mb2) = (Yt v2 sin2ß)/(Yb v2 cos2ß)=(Yt/Yb) tan2ß tan ß  53 for YtYb


53 Momentum dependence of annihilation cross section
v S-wave P-wave decoupling ns after BB M=60 GeV M=50 GeV

54 Expected SUSY mass spectra in mSUGRA for EGRET WIMP mass of 60 GeV
mSUGRA: common masses m0 and m1/2 for spin 0 and spin ½ particles

55 Gauge unification perfect with SUSY spectrum from EGRET
SM SUSY Update from Amaldi, dB, Fürstenau, PLB NO FREE PARAMETER WdB, C. Sander,PLB585(2004). e-Print: hep-ph/ With SUSY spectrum from EGRET + WMAP data and start values of couplings from final LEP data perfect gauge coupling unification! Also b->s and g-2 agree within 2σ with SUSY spectrum from EGRET


57 Coannihilations vs selfannihilation of DM
If it happens that other SUSY particles are around at the freeze-out time, they may coannihilate with DM. E.g. Stau + Neutralino -> tau Chargino + Neutralino -> W However, this requires extreme fine tuning of masses, since number density drops exponentially with mass. But more serious: coannihilaition will cause excessive boostfactors Since  anni = coanni + selfanni must yield <v>=10-26 cm3/s. This means if coannihilation dominates, selfannihilation  0 In present universe only selfannihilation can happen, since only lightest neutralino stable, other SUSY particles decayed, so no coannihilation. If selfannihilation x-section 0, no indirect detection.

58 0 Direct Detection of WIMPs
WIMPs elastically scatter off nuclei => nuclear recoils Measure recoil energy spectrum in target 0

59 Direct Detection of WIMPs

60 Direct Dark Matter Detection
CRESST ROSEBUD CUORICINO Phonons CDMS EDELWEISS CRESST II ROSEBUD ER HDMS GENIUS IGEX MAJORANA DRIFT (TPC) DAMA ZEPLIN I UKDM NaI LIBRA Ionization Scintillation XENON ZEPLIN II,III,IV Large spread of technologies: varies the systematic errors, important if positive signal! All techniques have equally aggressive projections for future performance But different methods for improving sensitivity L. Baudis, CAPP2003

61 Der Edelweiss Detektor
Messprinzip eines Halbleiter-Bolometers. Kommt es zu einem elastischen Stoß eines WIMP-Teilchens mit einem Atomkern des Germanium-Kristalls führt der Kern-Rückstoß zu einer Temperaturerhöhung des Kristalls, die über ein Thermometer registriert wird. Gleichzeitig ionisiert der Ge-Kern das Material in seiner Umgebung, was zu einem Ladungssignal führt, das an den Oberflächenelektroden ausgelesen wird.

62 Der Edelweiss Detektor

63 (in Frejus-Tunnel in französichen Alpen)
Edelweiss Experiment (in Frejus-Tunnel in französichen Alpen)

64 Schnelle (großflächige)
DM-Suche mit Tieftemperatur-Kalorimetern / CDMS Schnelle (großflächige) Auslese von Phononen Si oder Ge Einkristall Array von Phasenübergangs- Thermometern

65 Kalibration Kalibration eines Ge-Bolometers durch Bestrahlung mit einer 252Cf-Neutronenquelle: Deutlich erkennbar sind zwei Ereignispopulationen, die durch das Verhältnis von Ionisations- zu Rückstoß-Energie separiert werden können. Die auf das Ionisationssignal angelegte Energieschwelle (grüne Kurve) entspricht einer Rückstoßenergie von 3.5keV. Die Bänder beschreiben die Bereiche, in denen 90% der Elektron- bzw. Kern-Rückstöße liegen.

66 Der Edelweiss Detektor

67 Der XENON 10 Detektor

68 Der XENON 10 Detektor

69 Der XENON 10 Detektor

70 Der XENON 10 Detektor

71 Comparison with direct searches
CDMS Note: N90%CL=n <90%CLv> To get 90%CL one has to assume v and n : v assumed Maxwellian and NO corotation of DM halo n : assume DM mass from rotation curve to be completely diffuse. Theory: x-section can be order of magnitude lower due to matrix element uncertainties Conclusion: can easily move up exp. limits by order of magn. and move down theory by order of magnitude.

72 Large uncertainties in direct scattering x-section
Ellis, Olive, Savage, arXiv:

73 Annual Modulation as unique signature?
Annual modulation:   v, so signal in June larger than in December due to motion of earth around sun (5-9% effect). June v0 galactic center Sun 230 km/s Dec. June Dec ±2% Background WIMP Signal L. Baudis, CAPP2003

74 DAMA/NaI 1 to 7: Riv.N.Cim 26 n.1. (2003) 1-73
Schael, EPS2003 DAMA NaI-1 to 4: 58k kg.day DAMA NaI-5 to 7: 50k kg.day Full substitution of electronics and DAQ in 2000 The data favor the presence of a modulated signal with the proper features at the 6.3 σ C.L. Running conditions stable at level < 1%

75 Warum muss DM kalt sein, d.h. nicht-relativistisch? Antwort: Aus Galaxien- Dichteverteilung!


77 DM bildet Filamente erhöhter Dichte mit
Galaxien und Leerräumen dazwischen Simulation (jeder Punkt stellt eine Galaxie dar)  Steinmeitz, Potsdam





82 Kriterium für Gravitationskollaps: Jeans Masse und Jeans Länge
Gravitationskollaps einer Dichtefluktuation, wenn Expansionsrate 1/tExp  H  G langsamer als die Kontraktionsrate 1/tKon  vS / λJ ist. Oder die Jeanslänge (nach Jeans), d.h. die Länge einer Dichtefluktuation, die unter Einfluß der Gravitation wachsen kann, ist von der Größenordnung λJ = vs/ G (vS ist Schallgeschwindigkeit) (exakte hydrodynamische Rechnung gibt noch Faktor  größeren Wert) Nur in Volumen mit Radius λJ /2 Gravitationskollaps. Dies entspricht eine Jeansmasse von MJ = 4/3 (λJ/2)3  = (5/2 vs3 ) / (6G3/2)

83 Abfall der Schallgeschwindigkeit nach tr wenn Photonkoppelung wegfällt
Die Schallgeschwindigkeit fällt a) für DM wenn die Strahlungsdichte nicht mehr dominiert und b) für Baryonen nach der Rekombination um viele Größendordnungen (von c/3 für ein relat. Plasma auf 5T/3mp für Wasserstoff) D.h. DF die vor Rekombination stabil waren, kollabieren durch Gravitation. Galaxienbildung in viel kleineren Bereichen möglich, wenn vS klein!

84 Evolution of the universe
Early Universe Present Universe The Cosmic screen DT / T ~ Dr / r

85 Jeans Masse vs. Schallgeschwindigkeit

86 Top-down versus Bottom-up
Kleine Jeanslänge (non-relativistische Materie, Z.B. Neutralinos der Supersymmetrie) Große Jeanslänge (relativistische Materie, Z.B. Neutrinos mit kleiner Masse)

87 HDM (relativistisch  vS =c/3) versus CDM

88 Oder für gemischte DM Szenarien …
CDM WarmDM C+HDM Colombi, Dodelson, & Widrow 1995 Structure is smoothed out in model with light neutrinos


90 Millenium Simulation

91 Dunkle Materie, was wissen wir?
Was wissen wir über Dunkle Materie? massive Teilchen 23% der Energie des Universums schwache Wechselwirkung mit Materie Annihilation mit <σv>= cm3/s Annihilation in Quarkpaare -> Überschuss in galaktischen Gammastrahlen beobachtet? From CMB + SN1a LHC Experimente werden ab 2010 klären ob dies stimmt.

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