Astrophysical Motivations for Dark Forces. Jefferson Lab February 19, 2010 Neal Weiner Center for Cosmology and Particle Physics New York University

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1 Astrophysical Motivations for Dark Forces Jefferson Lab February 19, 2010 Neal Weiner Center for Cosmology and Particle Physics New York University

2 Era of data Cosmics: PAMELA, Fermi, ATIC, HESS, AMS, ACTs, WMAP, Planck... Direct: CDMS, DMTPC, XENON, LUX, CRESST, COUPP, PICASSO, KIMS... Production: LHC/Tevatron, Fixed Target, Beam dump

3 Era of anomalies G. Weidenspointner et al.: The sky distribution of positronium continuum emission

4 Era of anomalies Indications of high G. Weidenspointner et al.: The sky distribution of positronium continuum emission energy electron or 30 0 positron production 60

5 Anomalies and anomalies High Energy Electrons/Positrons: PAMELA (HEAT,AMS-01), ATIC, EGRET, WMAP Low energy positrons: INTEGRAL Direct detection: DAMA/LIBRA

6 Anomalies and anomalies High Energy Electrons/Positrons: PAMELA (HEAT,AMS-01), ATIC, EGRET, WMAP Low energy positrons: INTEGRAL Direct detection: DAMA/LIBRA multiple indications

7 The framework Recently a new framework has emerged, where DM annihilates not to the SM, but to some new force carrier (A, ϕ, a, U) χ f χ time f classic WIMP

8 The framework Recently a new framework has emerged, where DM annihilates not to the SM, but to some new force carrier (A, ϕ, a, U) χ f φ e χ time f time classic new, improved, WIMP WIMP e γ

9 The framework Recently a new framework has emerged, where DM annihilates not to the SM, but to some new force carrier (A, ϕ, a, U) TeV χ f φ e χ time f time classic new, improved, WIMP WIMP e γ

10 The framework Recently a new framework has emerged, where DM annihilates not to the SM, but to some new force carrier (A, ϕ, a, U) TeV χ f GeV φ e χ time f time classic new, improved, WIMP WIMP e γ

11 Dark Matter

13 what is it?

14 The WIMP miracle assume thermal equilibrium χχ ff χ f χ time f

15 The WIMP miracle assume thermal equilibrium χχ ff χ f χ time f

16 The WIMP miracle assume thermal equilibrium χχ ff χ f χ time f

17 The WIMP miracle assume thermal equilibrium χχ ff χ f χ time f

18 assume thermal equilibrium χχ ff When T<< M WIMP, number density falls as e -M/T

19 assume thermal equilibrium χχ ff When T<< M WIMP, number density falls as e -M/T Ωh cm 3 s 1 σv α 2 /(100GeV) 2 σv

20 assume thermal equilibrium χχ ff When T<< M WIMP, number density falls as e -M/T Ωh cm 3 s 1 σv α 2 /(100GeV) 2 σv Any weak- scale particle naturally freezes out within a few orders of magnitude of the correct cross section

21 Signals of thermal DM Production (accelerators) Cosmic rays/indirect detection (PAMELA/ Fermi/WMAP...) Direct detection (DAMA/XENON/CDMS...) χ f time χ time f

22 Signals of thermal dark matter Production (accelerators) Cosmic rays/indirect detection (PAMELA/Fermi/ WMAP...) Direct detection (DAMA/XENON/CDMS...) time χ χ time f f

23 The step-child of dark matter anomalies: INTEGRAL INTEGRAL/ SPI: (spectrometer) Energy range: 20 kev - 8 MeV Field of view: 16 deg Angular resolution: 2.5 deg FWHM Launched: 2002 Oct 17 Still operating...

24 distribution of the INTEGRAL 511 kev line

25 The step-child of dark matter anomalies: INTEGRAL 10 3 Diff. Flux [1/cm 2 /s/kev] Must be injected with low energies to give narrow line shape Energy [kev] Fig. 2. A fit of the SPI result for the diffuse emission from the GC region ( l, b 16 ) obtained with a spatial model consisting of an 8 FWHM Gaussian bulge and a CO disk. In the fit a diagonal response was assumed. The spectral components are: 511 kev line (dotted), Ps continuum (dashes), and power-law continuum (dash-dots). The summed models are indicated by the solid line. Details of the fitting procedure are given in the text.

26 exciting DM (XDM) D.Finkbeiner, NW, Phys.Rev.D76:083519,2007 Suppose TeV mass dark matter has an excited state ~ MeV above the ground state, and a new force φ with mass ~ GeV through which DM can scatter into the excited state, then decay back by emitting e+e- χ 1 χ 2 χ 2 χ 1 φ φ e χ 1 χ 2 ē

27 Need cross section near the geometric cross section, i.e. σ 1/q 2 Only possible if new force with mass m φ < GeV 2 is in the theory

28 The NKOTB of dark matter anomalies: PAMELA

29 The NKOTB of dark matter anomalies: PAMELA

30 The NKOTB of dark matter anomalies: PAMELA

31 PAMELA

32 PAMELA

33 Fermi, HESS, ATIC, PPB-BETS Harder spectrum than expected - no break until ~ TeV

34 Positrons expected from secondary production

35 How do electrons propagate? what we want to know diffusion (not well understood) ICS and synchrotron energy losses (fairly well understood)

36 Grajek, Kane, Pierce, Phalen, 08

37 Hooper + Simet 09

39 Astrophysics? Malyshev, Cholis, Gelfand, 09 Aharonian, Atoyan, Volk 95; Hooper, Blasi, Serpico 08;Profumo 09...

40 DM or Astrophysics? (look in the inner galaxy)

41 WMAP

43 Interstellar Dust from IRAS, DIRBE (Finkbeiner et al. 1999) Map extrapolated from 3 THz (100 micron) with FIRAS.

44 Ionized Gas from WHAM, SHASSA, VTSS (Finkbeiner 2003) H-alpha emission measure goes as thermal bremsstrahlung.

45 Synchrotron at 408 MHz (Haslam et al. 1982)

46 K (23GHz) Ka (33GHz) Q (41GHz) V (61 GHz) W (94 GHz) Template +90 b CMB b Halpha b b b b SoftSynch FDS dust FDS * T^2 Haze b Mask l l l l l l -90 Fig. 1. The WMAP foreground grid; see detailed discussion in 2.7.

47 Dobler and Finkbeiner 08

48 Dobler and Finkbeiner 08

49 A Haze Dobler and Finkbeiner 08

50 A Haze Dobler and Finkbeiner 08 electrons spiraling in magnetic field create microwaves

51 WMAP Haze (Finkbeiner 2004; Dobler&Finkbeiner 2008) pulsars dark matter plots courtesy G. Dobler

center, but with larger amplitude than locally pulsars good

52 WMAP Haze (Finkbeiner 2004; Dobler&Finkbeiner 2008) Natural interpretation is of new source of 10+ GeV e+e-in galactic center, but with larger amplitude than locally pulsars good fit for DM explanation dark matter plots courtesy G. Dobler

53 Fermi ICS In the inner galaxy, high energy e+e- convert energy to synchrotron radiation (WMAP haze) and inverse-compton scattered photons starlight e gamma ray e Same electrons should upscatter starlight into gamma rays

55 90 SFD Dust 90 Fermi ICS Haslam 408 MHz Haze template GeV observed GeV synthetic GeV observed minus synthetic

90 2-5 GeV residual 90 2-5 GeV residual, with template 45

5-10 GeV residual 90 5-10 GeV residual, with template 45

45 20-50 GeV residual 90 20-50 GeV residual, with

56 GeV residual GeV residual, with template GeV residual GeV residual, with template GeV residual GeV residual, with template GeV residual GeV residual, with template

57 Hints of high energy e + e - PAMELA tells us that there is a primary source of GeV positrons within 1kpc Fermi indicates an excess of e + e - up to ~ 1 TeV (ATIC as well) The WMAP Haze suggests us that there is a new population of GeV positrons in the galactic center (5-15 ) Fermi gamma rays seem also to indicate high energy electron production in galactic center NB: Hard analyses!

58 WIMP annihilations? Not so fast!

59 WIMP annihilations? Not so fast! PAMELA sees no excess in antiprotons - excludes hadronic modes by order of magnitude (Cirelli et al, 08, Donato et al, 08)

60 WIMP annihilations? Not so fast! PAMELA sees no excess in antiprotons - excludes hadronic modes by order of magnitude (Cirelli et al, 08, Donato et al, 08)

61 WIMP annihilations? Not so fast! PAMELA sees no excess in antiprotons - excludes hadronic modes by order of magnitude (Cirelli et al, 08, Donato et al, 08) The spectrum at PAMELA is very hard - not what you would expect from e.g., W s

62 WIMP annihilations? Not so fast! PAMELA sees no excess in antiprotons - excludes hadronic modes by order of magnitude (Cirelli et al, 08, Donato et al, 08) The spectrum at PAMELA is very hard - not what you would expect from e.g., W s

63 WIMP annihilations? Not so fast! PAMELA sees no excess in antiprotons - excludes hadronic modes by order of magnitude (Cirelli et al, 08, Donato et al, 08) The spectrum at PAMELA is very hard - not what you would expect from e.g., W s

64 WIMP annihilations? Not so fast! PAMELA sees no excess in antiprotons - excludes hadronic modes by order of magnitude (Cirelli et al, 08, Donato et al, 08) The spectrum at PAMELA is very hard - not what you would expect from e.g., W s The cross sections needed are x the thermal

65 WIMP annihilations? Not so fast! PAMELA sees no excess in antiprotons - excludes hadronic modes by order of magnitude (Cirelli et al, 08, Donato et al, 08) The spectrum at PAMELA is very hard - not what you would expect from e.g., W s The cross sections needed are x the thermal

66 The three ingredients to explain PAMELA/Fermi

67 The three ingredients to explain Hard lepton spectrum PAMELA/Fermi

68 The three ingredients to explain PAMELA/Fermi Hard lepton spectrum Few/no anti-protons

69 The three ingredients to explain PAMELA/Fermi Hard lepton spectrum Few/no anti-protons Large cross section (much larger than thermal - for annihilation)

70 The three ingredients to explain PAMELA/Fermi Hard lepton spectrum Few/no anti-protons Large cross section (much larger than thermal - for annihilation) All these can be explained by insisting that the dark matter has a new GeV scale force (Arkani-Hamed, Finkbeiner, Slatyer, NW, 08)

71 The three ingredients to explain PAMELA/Fermi Hard lepton spectrum Few/no anti-protons Large cross section (much larger than thermal - for annihilation) All these can be explained by insisting that the dark matter has a new GeV scale force (Arkani-Hamed, Finkbeiner, Slatyer, NW, 08) Wide range of models all share similar structure (Pospelov and Ritz, 08; Fox and Poppitz 08; Nomura and Thaler 08; Nelson and Spitzer 08; Katz and Sundrum 08...)

72 New forces = new annihilation modes Finkbeiner, NW PRD 07; Pospelov, Ritz, Voloshin PLB 08 Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

73 New forces = new annihilation modes Finkbeiner, NW PRD 07; Pospelov, Ritz, Voloshin PLB 08 f f Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

74 New forces = new annihilation modes Finkbeiner, NW PRD 07; Pospelov, Ritz, Voloshin PLB 08 f f WIMP Miracle works as before (sigma ~ 1/M 2 ) No antiprotons comes from kinematics Hard positrons come from highly boosted φ s/a s Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

75 New forces = new annihilation modes Finkbeiner, NW PRD 07; Pospelov, Ritz, Voloshin PLB 08 WIMP Miracle works as before (sigma ~ 1/M 2 ) No antiprotons comes from kinematics Hard positrons come from highly boosted φ s/a s Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

76 New forces = new annihilation modes Finkbeiner, NW PRD 07; Pospelov, Ritz, Voloshin PLB 08 Cholis, Goodenough, NW, arxiv: Pre-PAMELA WIMP Miracle works as before (sigma ~ 1/M 2 ) No antiprotons comes from kinematics Hard positrons come from highly boosted φ s/a s Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

77 New forces = new annihilation modes Finkbeiner, NW PRD 07; Pospelov, Ritz, Voloshin PLB 08 Cholis, Goodenough, NW, arxiv: Pre-PAMELA Cholis, et al, arxiv: Post-PAMELA WIMP Miracle works as before (sigma ~ 1/M 2 ) No antiprotons comes from kinematics Hard positrons come from highly boosted φ s/a s Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

78 Sommerfeld Enhancement High velocity Hisano, Nojiri, Matsumoto 04; Cirelli & Strumia 07; Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

79 Sommerfeld Enhancement High velocity Low velocity Hisano, Nojiri, Matsumoto 04; Cirelli & Strumia 07; Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

80 Sommerfeld Enhancement High velocity Low velocity Hisano, Nojiri, Matsumoto 04; Cirelli & Strumia 07; Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

81 Sommerfeld Enhancement High velocity Low velocity If particles interact via a long range force, cross sections can be much larger than the perturbative cross section Hisano, Nojiri, Matsumoto 04; Cirelli & Strumia 07; Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

82 Sommerfeld Enhancement High velocity Low velocity If particles interact via a long range force, cross sections can be much larger than the perturbative cross section If these signals arise from thermal dark matter, dark matter must have a long range force Hisano, Nojiri, Matsumoto 04; Cirelli & Strumia 07; Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

83 Sommerfeld Enhancement High velocity Low velocity If particles interact via a long range force, cross sections can be much larger than the perturbative cross section If these signals arise from thermal dark matter, dark matter must have a long range force m 1 φ > (αm DM ) 1 (fm) Hisano, Nojiri, Matsumoto 04; Cirelli & Strumia 07; Arkani-Hamed, Finkbeiner, Slatyer, NW, 08

85 E 3 dn/de (GeV 2 m -2 s -1 sr -1 ) HESS Systematic Error Band HESS Data Fermi Data ATIC Data m = 1.6 TeV, BF = 370 (DM + Background) m = 600 GeV, BF = 99 (DM + Background) m = 200 GeV, BF = 18 (DM + Background) Background XDM e + e - µ + µ + (1:1:2) Channel e + / ( e + + e -) m = 1.6 TeV, BF = 650 m = 600 GeV, BF = 110 m = 200 GeV, BF = 20 Background PAMELA Data DM Contribution XDM e + e - µ + µ + (1:1:2) Channel Energy (GeV) Energy (GeV) Intensity (10-20 erg sec -1 Hz -1 cm -2 sr -1 ) m =1.6 TeV, BF = 660 m = 600 GeV, BF = 102 m = 200 GeV, BF = 16 Haze Data XDM e + e - µ + µ + (1:1:2) Channel Latitudinal Radial Distance from GC (degrees)

86 How natural the GeV scale? Interactions with Α'1 Α'10 2 Α'10 4 Α' GeV 100 GeV standard model 1 GeV mass scale Α' 12 1 GeV generate scales 10 MeV mass scale Α' 10 MeV Α'1 Α'10 2 Α'10 4 Α'10 6 Works most naturally with new physics models (SUSY, Randall-Sundrum, etc)

87 Searching for WIMPs

88 Searching for WIMPs How to detect a WIMP?

89 Searching for WIMPs How to detect a WIMP? Step 1: Build big detector

90 Searching for WIMPs How to detect a WIMP? Step 1: Build big detector How big?

91 Searching for WIMPs How to detect a WIMP? Step 1: Build big detector How big?

92 Searching for WIMPs How to detect a WIMP? Step 1: Build big detector How big? rate few events kg year σ v cm 2 300km/s

93 Searching for WIMPs How to detect a WIMP? Step 1: Build big detector How big? rate few events kg year σ v cm 2 300km/s

94 Searching for WIMPs How to detect a WIMP? Step 1: Build big detector How big? rate few events kg year σ v cm 2 300km/s Step II: Go deep underground to shield from cosmic rays

95 Searching for WIMPs How to detect a WIMP? Step 1: Build big detector How big? rate few events kg year σ v cm 2 300km/s Step II: Go deep underground to shield from cosmic rays Step III: Have no other background

96 seasonal variation WIMP wind as galaxy rotates, we experience a WIMP wind Drukier, Freese, Spergel Phys.Rev.D33: ,1986

97 seasonal variation in the summer, WIMP wind moving against wind expect an annual modulation in signal! in the winter, moving against wind Drukier, Freese, Spergel Phys.Rev.D33: ,1986

98 Bernabei et al., Eur.Phys.J.C56: ,2008 DAMA experiment 8.3 sigma signal for modulation only in single hit events proper phase Dark matter?

99 Bernabei et al., Eur.Phys.J.C56: ,2008 DAMA experiment 8.3 sigma signal for modulation only in single hit events Angle et al, Phys.Rev.Lett.100:021303,2008 proper phase Dark matter?

Bernabei et al., Eur.Phys.J.C56:333-355,2008 DAMA experiment 8.3 sigma signal for modulation only in single hit events proper phase Dark matter?

100 Bernabei et al., Eur.Phys.J.C56: ,2008 DAMA experiment 8.3 sigma signal for modulation only in single hit events proper phase Dark matter? Cross-section [cm 2 ] (normalised to nucleon) WIMP Mass [GeV/c 2 ] Angle et al, Phys.Rev.Lett.100:021303, Gaitskell,Mandic,Filippini DATA listed top to bottom on plot CDMS (Soudan) 2005 Si (7 kev threshold) KIMS kg-days CsI Edelweiss I final limit, 62 kg-days Ge DAMA k kg-days NaI Ann. Mod. 3sigma w WARP 2.3L, 96.5 kg-days 55 kev threshold CRESST kg-day CaWO4 ZEPLIN III (Dec 2008) result CDMS: (reanalysis) Ge XENON (Net 136 kg-d)

101 Consider vector interaction χ 1 σ µ χ 1 A µ χ 1 χ 1 A µ

102 Consider vector interaction χ 1 σ µ χ 1 A µ χ 1 χ 1 A µ

103 Consider vector interaction χ 1 σ µ χ 1 A µ χ 1 σ µ χ 2 A µ χ 1 χ 2 χ 1 χ 1 A µ A µ

104 Consider vector interaction χ 1 σ µ χ 1 A µ χ 1 σ µ χ 2 A µ χ 1 χ 2 χ 1 χ 1 A µ A µ Vector interactions for massive WIMPs (M DM >M force ) always require multiple states interaction is off-diagonal

105 Question: δ

106 Question: What is the splitting between those states? δ

107 Question: What is the splitting between those states? δ Tiny?

108 Question: What is the splitting between those states? δ Tiny? Comparable to WIMP kinetic energy?

109 Question: What is the splitting between those states? δ Tiny? Comparable to WIMP kinetic energy? Huge?

110 Question: What is the splitting between those states? δ Tiny? Comparable to WIMP kinetic energy? Huge? For Sommerfeld Enhancement (i.e., PAMELA), states must be small

111 Question: What is the splitting between those states? δ Tiny? Comparable to WIMP kinetic energy? Huge? For Sommerfeld Enhancement (i.e., PAMELA), states must be small δ M < α2 4 For α 10 2 M TeV δ 100MeV kinetic energy of a WIMP

112 Inelastic dark matter D.Tucker-Smith, NW, Phys.Rev.D64:043502,2001;Phys.Rev.D72:063509,2005 DM-nucleus scattering must be inelastic If dark matter can only scatter off of a nucleus by transitioning to an excited state (100 kev), the kinematics are changed dramatically χ χ N N

113 Inelastic dark matter D.Tucker-Smith, NW, Phys.Rev.D64:043502,2001;Phys.Rev.D72:063509,2005 DM-nucleus scattering must be inelastic If dark matter can only scatter off of a nucleus by transitioning to an excited state (100 kev), the kinematics are changed dramatically χ χ N N

114 Favors heavier targets visible to DAMA visible to DAMA and CDMS Disfavors CDMS

115 Enhanced modulation Favors modulation experiments

116 Modified spectrum Together, these three effects allow a positive DAMA signal consistent with XENON/CDMS/ CRESST/KIMS...

117 A new force in the dark sector Outputs > Inputs GeV mediator gives all aspects of the anomalies (size, leptons, no antiprotons) Non-Abelian or multi-state models give natural explanation for all anomalies (INTEGRAL, DAMA, and e+e-)

118 Perspective

119 Unreliable astrophysical signals can be the first sign of new physics

120 The future of beyond the standard model physics? Α'1 Α'10 2 Α'10 4 Α' GeV 100 GeV 1 GeV mass scale Α' 12 1 GeV 10 MeV mass scale Α' 10 MeV Α'1 Α'10 2 Α'10 4 Α'10 6

121 The future of beyond the standard model physics? New physics (SUSY, etc) energy frontier Standard model Dark sector luminosity frontier

122 Motivating dark forces

123 Motivating dark forces A wealth of anomalies can be explained by the presence of a new, dark force

124 Motivating dark forces A wealth of anomalies can be explained by the presence of a new, dark force Single ingredient: new dark force at ~ GeV addresses key issues Large excitation cross section for INTEGRAL Hard leptons/no antiprotons for PAMELA/Fermi Large Annihilation cross section Excited states for DAMA/INTEGRAL

125 Motivating dark forces A wealth of anomalies can be explained by the presence of a new, dark force Single ingredient: new dark force at ~ GeV addresses key issues Large excitation cross section for INTEGRAL Hard leptons/no antiprotons for PAMELA/Fermi Large Annihilation cross section Excited states for DAMA/INTEGRAL Testable

126 Thank you very much!

127 Supplemental Slides

128 Spectra in realistic halos Kuhlen & NW, in prep DAMA, 100 GeV, 130 kev CRESST (norm to 1), 100 GeV, 130 kev Yellin techniques (optimum interval, maximum gap, pmax) unreliable for inelastic models in experiments with good energy resolution

Limits from galactic center Interesting limits from bremmed photons (Beacom, Bell, Bertone, 04; Bell & Jacques 08; Bertone, Cirelli, Strumia, Taoso, 08; Bergstrom, Bertone, Bringmann, Edsjo, Taoso,

129 Limits from galactic center Interesting limits from bremmed photons (Beacom, Bell, Bertone, 04; Bell & Jacques 08; Bertone, Cirelli, Strumia, Taoso, 08; Bergstrom, Bertone, Bringmann, Edsjo, Taoso, 08; Meade, Papucci, Volansky, 09; Mardon, Nomura, Stolarski, Thaler, 09) Limits rely on knowing density and velocity in GC - can change a lot with baryons! Governato et al, 2006 Romano-Diaz, Schlosman, Hoffman, Heller, 08 NB: Many simulation uncertainties (matching bulge with MW, other numerical issues involving baryons)

130 GOING FORWARD Planck Padmanabhan&Finkbeiner 04; Bertone, Galli, Iocco, Melchiorri, 09;Slatyer, Finkbeiner, Padmanabhan 09 Should definitively test DM electronic production

Astrophysical Detection of Dark Matter

Astrophysical Detection of Dark Matter Doug Finkbeiner, Harvard Tracy Slatyer Tongyan Lin Lauren Weiss David Rosengarten Neal Weiner, NYU Ilias Cholis Lisa Goodenough What am I doing here? Michigan undergrad: