Signals of Dark Forcesat Fermi
Neal Weiner
Center for Cosmology and Particle Physics
New York University
Fermi Symposium, Washington DC
November 4, 2009

Wednesday, November 4, 2009

DM in the Era of Data
A wide range of experiments have seen
significant signals
These signals are hard to understand in
traditional WIMP models
A new framework has emerged with dramatic
signal arising from new interactions in thedark sector

Wednesday, November 4, 2009

The WIMP “miracle”
assume thermal
¯
χχ
↔
f
f
equilibrium

Wednesday, November 4, 2009

χ

f

χ

f¯
←− time −→The WIMP “miracle”
assume thermal
¯
χχ
↔
f
f
equilibrium

When T<< MWIMP, number-M/Tdensity falls as eΩh ≈ 0.1 ×2

�≈ 0.1 ×
Wednesday, November 4, 2009

3 × 10

�

−26

2

3 −1

cm s
�σv�

2

α /(100GeV)
�σv�

�

�

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

f

χ

f¯

←− time −→χ

Wednesday, November 4, 2009←− time −→Era of anomalies
2 - 5 GeV residual
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1016

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

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Fig. 1. A Richardson-Lucy sky map of extended emission in the summed Ps analysis intervals (the combination of the intervals 410–430,
447−465, and 490–500 keV). The contour levels indicate intensity levels of 10−2 , 10−3 , and 10−4 ph cm−2 s−1 sr−1 . Details are given in the text.

Wednesday, November 4,the2009
combined effects of statistical and systematic biases in theabove about 300 keV, and since we are analyzing rather nar-

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2 - 5 GeV residual
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1016

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

60
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0

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225

270

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0

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Fig. 1. A Richardson-Lucy sky map of extended emission in the summed Ps analysis intervals (the combination of the intervals 410–430,
447−465, and 490–500 keV). The contour levels indicate intensity levels of 10−2 , 10−3 , and 10−4 ph cm−2 s−1 sr−1 . Details are given in the text.

Wednesday, November 4,the2009
combined effects of statistical and systematic biases in theabove about 300 keV, and since we are analyzing rather nar-

Indications of highenergy electron or
positron production

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9090WIMP annihilations?
Not so fast

Wednesday, November 4, 2009

WIMP annihilations?
Not so fast
PAMELA sees no excess inantiprotons - excludes
hadronic modes by order ofmagnitude (Cirelli et al, ’08, Donato et al, ’08)

Wednesday, November 4, 2009

WIMP annihilations?
Not so fast
PAMELA sees no excess inantiprotons - excludes
hadronic modes by order ofmagnitude (Cirelli et al, ’08, Donato et al, ’08)

Wednesday, November 4, 2009

WIMP annihilations?
Not so fast
PAMELA sees no excess inantiprotons - excludes
hadronic modes by order ofmagnitude (Cirelli et al, ’08, Donato et al, ’08)
The spectrum at Fermi/
PAMELA is very hard - notwhat you would expectfrom e.g., W’s

Wednesday, November 4, 2009

WIMP annihilations?
Not so fast
PAMELA sees no excess inantiprotons - excludes
hadronic modes by order ofmagnitude (Cirelli et al, ’08, Donato et al, ’08)
The spectrum at Fermi/
PAMELA is very hard - notwhat you would expectfrom e.g., W’s

Wednesday, November 4, 2009

WIMP annihilations?
Not so fast
PAMELA sees no excess inantiprotons - excludes
hadronic modes by order ofmagnitude (Cirelli et al, ’08, Donato et al, ’08)
The spectrum at Fermi/
PAMELA is very hard - notwhat you would expectfrom e.g., W’s

Wednesday, November 4, 2009

WIMP annihilations?
Not so fast
PAMELA sees no excess inantiprotons - excludes
hadronic modes by order ofmagnitude (Cirelli et al, ’08, Donato et al, ’08)
The spectrum at Fermi/
PAMELA is very hard - notwhat you would expectfrom e.g., W’s
The cross sections neededare 10-1000x the thermal
Wednesday, November 4, 2009

WIMP annihilations?
Not so fast
PAMELA sees no excess inantiprotons - excludes
hadronic modes by order ofmagnitude (Cirelli et al, ’08, Donato et al, ’08)
The spectrum at Fermi/
PAMELA is very hard - notwhat you would expectfrom e.g., W’s
The cross sections neededare 10-1000x the thermal
Wednesday, November 4, 2009

The three ingredients to explain
PAMELA/Fermi

Wednesday, November 4, 2009

The three ingredients to explain
PAMELA/Fermi
Hard lepton spectrum

Wednesday, November 4, 2009

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

Wednesday, November 4, 2009

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

Wednesday, November 4, 2009

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

Wednesday, November 4, 2009

The XDM framework

Finkbeiner, NW astro-ph/0702587

Wednesday, November 4, 2009

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited states
eXtra dark forces
eXtreme cosmic ray signatures

Wednesday, November 4, 2009

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited states
eXtra dark forces
eXtreme cosmic ray signatures

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited states
eXtra dark forces
eXtreme cosmic ray signatures
χ

f

χ

f¯
←− time −→“classic”
WIMP
cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited states
eXtra dark forces
eXtreme cosmic ray signatures
χ

f

χ

f¯
←− time −→“classic”
WIMP←− time −→XDM

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited states
eXtra dark forces
eXtreme cosmic rayTeV
signatures
χ

f

χ

f¯
←− time −→“classic”
WIMP←− time −→XDM

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited states
eXtra dark forces
eXtreme cosmic rayTeV
signatures
f

χ

GeV
χ

f¯
←− time −→“classic”
WIMP←− time −→XDM

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited statesφeeXtra dark forces
eXtreme cosmic rayTeV
signaturesequilibrium
+
f

χ

GeV e
χ

f¯
←− time −→“classic”
WIMP←− time −→XDM

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

γ

The XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited statesφeeXtra dark forces
eXtreme cosmic rayTeV
signaturesequilibrium
+
f

χ

GeV e
χ

γ

f¯
←− time −→“classic”
WIMP←− time −→XDM

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

+

f

φ
CR
signaturesfThe XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited statesφeeXtra dark forces
eXtreme cosmic ray signaturesequilibrium
+
f

χ

e
χ

γ

f¯
←− time −→“classic”
WIMP←− time −→XDM

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009

+

f

φ
CR
signaturesfThe XDM framework

XDM:
Finkbeiner, NW astro-ph/0702587
eXcited statesφeeXtra dark forces
eXtreme cosmic ray signaturesequilibrium
+
f

χ

e
χ

γ

f¯
←− time −→“classic”
WIMP

Finkbeiner + NW ’07←− time −→XDM

cf generalizations Pospelov, Ritz, Voloshin, arxiv:0711.4866;e+e- signatures Cholis, Goodenough, NW 0802.2922
Wednesday, November 4, 2009+φCR
signaturesffNew forces = new annihilation modes
Finkbeiner, NW PRD ’07

Arkani-Hamed, Finkbeiner, Slatyer, NW, ‘08
Wednesday, November 4, 2009

New forces = new annihilation modes
Finkbeiner, NW PRD ’07“WIMP Miracle” works as before (sigma ~ 1/M2)
No antiprotons from kinematics
Hard positrons come from highly boosted φ’s
Arkani-Hamed, Finkbeiner, Slatyer, NW, ‘08
Wednesday, November 4, 2009

New forces = new annihilation modes
Finkbeiner, NW PRD ’07

Cholis, Goodenough, NW, arxiv:0802.2922

Pre-PAMELA“WIMP Miracle” works as before (sigma ~ 1/M2)
No antiprotons from kinematics
Hard positrons come from highly boosted φ’s
Arkani-Hamed, Finkbeiner, Slatyer, NW, ‘08
Wednesday, November 4, 2009

New forces = new annihilation modes
Finkbeiner, NW PRD ’07

Cholis, Goodenough, NW, arxiv:0802.2922

Pre-PAMELA

Cholis, et al, arxiv:0810.5344

Post-PAMELA“WIMP Miracle” works as before (sigma ~ 1/M2)
No antiprotons from kinematics
Hard positrons come from highly boosted φ’s
Arkani-Hamed, Finkbeiner, Slatyer, NW, ‘08
Wednesday, November 4, 2009Sommerfeld Enhancement

High velocity

Wednesday, November 4, 2009Sommerfeld Enhancement

High velocity

Low velocity

Wednesday, November 4, 2009Sommerfeld Enhancement

High velocity

Low velocity

Wednesday, November 4, 2009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

Wednesday, November 4, 2009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

Wednesday, November 4, 2009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
long ~ fm
Wednesday, November 4, 2009

Wednesday, November 4, 2009

Wednesday, November 4, 2009

A new force carrier
Dark matter interacting with a new force
naturally explains the cosmic ray signatures
Large cross section (Sommerfeld)
Lots of leptons (too light to go into muchelse)
No anti-protons (too light to make them)Wednesday, November 4, 2009ICS gamma rays should
show change in index athigh energies

Inner galaxy(ISRF) Porter et al, ApJ 682 08;(Connections to PAMELA) Cholis et al, 0811.3641; Zhang
et al, arXiv:0812.0522; Borriello, Cuoco, Miele, arXiv:
0903.1852; Regis, Ulio arXiv:0904.4645 ; Cirelli, Panci
arXiv:0904.3830; Meade, Papucci, Strumia, Volansky,
arxiv: 0905.0480; Cholis et al arxiv:0907.3953
Borriello, Cuoco, Miele, arXiv:0903.1852
Wednesday, November 4, 2009

A Regression Analysis

Dobler et al, ’09

Can approach the inner galaxy with simple(but physical) approach
Use spatial morphology to address
backgrounds
SFD dust map as tracer of of pions, Haslam
as tracer of (soft) ICS

Wednesday, November 4, 2009

Wednesday, November 4, 2009

The Fermi Haze

Template analysis indicates hardening ofelectron spectrum in IG
A long way from knowing the origin, but
could have been a strong constraint
Wednesday, November 4, 2009

DM in the era ofanomalies

Wednesday, November 4, 2009

DM in the era ofanomalies
A wide range of anomalies have forced us toreconsider our assumptions about DM

Wednesday, November 4, 2009

DM in the era ofanomalies
A wide range of anomalies have forced us toreconsider our assumptions about DM
Large electronic excesses at Fermi/PAMELA
require large rates of lepton production

Wednesday, November 4, 2009

DM in the era ofanomalies
A wide range of anomalies have forced us toreconsider our assumptions about DM
Large electronic excesses at Fermi/PAMELA
require large rates of lepton production
New GeV mass force can give boost without
appealing to substructure and e+e- throughkinematics

Wednesday, November 4, 2009

DM in the era ofanomalies
A wide range of anomalies have forced us toreconsider our assumptions about DM
Large electronic excesses at Fermi/PAMELA
require large rates of lepton production
New GeV mass force can give boost without
appealing to substructure and e+e- throughkinematics
Diffuse emission may hold hints of DM, but too
early to say
Wednesday, November 4, 2009

Thanks to the Fermi
Collaboration!

Wednesday, November 4, 2009

Wednesday, November 4, 2009

Slatyer, Finkbeiner,
Padmanabhan ’09

Finkbeiner and Padmanabhan ’05
Wednesday, November 4, 2009

Galli, Iocco, Bertone, Melchiorri ’09

Wednesday, November 4, 2009

Going Forward
PlanckSlatyer, Finkbeiner,
Padmanabhan ’09

Should definitively test DM electronic production
Wednesday, November 4, 2009

Wednesday, November 4, 2009

INTEGRAL

LMXB’s having some trouble: Private communcation: P. Ubertini
Wednesday, November 4, 2009

distribution of the INTEGRAL 511 keV line

Wednesday, November 4, 2009

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 throughwhich DM can scatter into the excited state,then decay back by emitting e+eχ2

χ1

φ
χ1

χ1
χ2

φ

e

χ2

ē
Wednesday, November 4, 2009

Need cross section near thegeometric cross section, i.e.
σ ∼ 1/q 2

Only possible if new force with mass2
mφ < GeV is in the theory

Wednesday, November 4, 2009

Velocities in the GC

Governato et al, 2006

Romano-Diaz, Schlosman, Hoffman, Heller, ‘08

Also Navarro et al (’09, private communication)

Increased velocities make XDM explanations workover broader range of parameters
Wednesday, November 4, 2009

Wednesday, November 4, 2009

WMAP

Wednesday, November 4, 2009

Wednesday, November 4, 2009

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

Wednesday, November 4, 2009

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

Wednesday, November 4, 2009

Synchrotron at 408 MHz (Haslam et al. 1982)

Wednesday, November 4, 2009

K (23GHz)

Ka (33GHz)

Q (41GHz)V (61 GHz)W (94 GHz)

Template

+90

CMB

b
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b
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b
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b
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b
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b
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l

-90 90l-90 90l-90 90l-90 90l-90 90Fig. 1.— The WMAP foreground grid; see detailed discussion in §2.7.

Wednesday, November 4, 2009l-90

Dobler and Finkbeiner ’08

Wednesday, November 4, 2009

Dobler and Finkbeiner ’08

Wednesday, November 4, 2009

WMAP Haze (Finkbeiner 2004;
Dobler&Finkbeiner 2008)

pulsarsdarkmatterplots courtesy G. Dobler

Wednesday, November 4, 2009

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 locallypulsars
Wednesday, November 4, 2009

dark
mattergood fit for DM explanation
plots courtesy G. Dobler

Wednesday, November 4, 2009

1 - 2 GeV

2 - 5 GeV

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Backgrounds

Wednesday, November 4, 2009

Wednesday, November 4, 2009

Fermi ICS

SFD Dust

Haslam 408 MHz

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Wednesday, November 4, 2009

Wednesday, November 4, 2009

DAMA experiment

Bernabei et al., Eur.Phys.J.C56:333-355,2008

8.3 sigma signal for modulation
proper phase

Dark matter?

-40

Cross-section [cm2] (normalised to nucleon)

only in “single hit” events

Angle et al, Phys.Rev.Lett.100:021303,200810

http://dmtools.brown.edu/
Gaitskell,Mandic,Filippini
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1010Wednesday, November 4, 2009DATA listed top to bottom on plot
CDMS (Soudan) 2005 Si (7 keV threshold)
KIMS 2007 - 3409 kg-days CsI
Edelweiss I final limit, 62 kg-days Ge 2000+2002+
DAMA 2000 58k kg-days NaI Ann. Mod. 3sigma w
WARP 2.3L, 96.5 kg-days 55 keV threshold
CRESST 2007 60 kg-day CaWO4ZEPLIN III (Dec 2008) result
CDMS: 2004+2005 (reanalysis) +2008 Ge
XENON10 2007 (Net 136 kg-d)

-43

10

1

090318234201

2

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WIMP Mass [GeV/c2]

103

Consider vector interaction
χ1 σµ χ1 Aµ

χ1
χ1

A

Wednesday, November 4, 2009µConsider vector interaction
χ1 σµ χ1 Aµ

χ1
χ1

A

Wednesday, November 4, 2009µConsider vector interaction
χ1 σµ χ1 Aµ

χ1 σµ χ2 Aµ

χ1
χ1

χ1

A

Wednesday, November 4, 2009

χ2

µ

A

µ

Consider vector interaction
χ1 σµ χ1 Aµ

χ1 σµ χ2 Aµ

χ1
χ1

χ2
χ1

A

µ

A

µ

Vector interactions for massive WIMPs(MDM>Mforce) always require multiple statesinteraction is off-diagonal
Wednesday, November 4, 2009

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

δ < α2∼M
4
Wednesday, November 4, 2009

For α ∼ 10−2

M ∼ T eVδ ∼ 10 MeV ∼ kinetic energy of a WIMP

“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), thekinematics are changed dramatically
∗

χ

χ

N
N
Wednesday, November 4, 2009

“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), thekinematics are changed dramatically
∗

χ

χ

N
N
Wednesday, November 4, 2009

Favors heavier targets

visible to DAMA
visible to DAMA
and CDMS

Disfavors CDMS
Wednesday, November 4, 2009

Enhanced modulation

Favors modulation experiments
Wednesday, November 4, 2009

Modified spectrum

How robust arethese effects?

Wednesday, November 4, 2009

Wednesday, November 4, 2009