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From CMB + SN1a + structure formation. EGRET excess of diffuse Galactic Gamma Rays interpreted as Dark Matter Annihilation. Wim de Boer, Christian Sander, Valery Zhukov Univ. Karlsruhe Dmitri Kazakov, Alex Gladyshev Dubna. Outline (see astro-ph/0408272)

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slide1

From CMB + SN1a +

structure formation

EGRET excess of diffuse Galactic Gamma Rays

interpreted as Dark Matter Annihilation

Wim de Boer, Christian Sander, Valery Zhukov

Univ. Karlsruhe

Dmitri Kazakov, Alex Gladyshev

Dubna

  • Outline (see astro-ph/0408272)
  • EGRET Data on diffuse Gamma Rays show excess in all sky directions with the SAME energy spectrum from monoenergetic quarks
  • WIMP massbetween 50 and 100 GeV from spectrum of EGRET excess
  • Halo distribution from sky map
  • Data consistent with Supersymmetry
dm annihilation in supersymmetry

f

f

f

~

f

A

Z

f

f

f

W

Z

0



Z

W

DM annihilation in Supersymmetry

≈ 37

gammas

B-fragmentation well studied at LEP!

Yield and spectra of positrons,

gammas and antiprotons well known!

Dominant diagram for WMAP

cross section in MSSM:

 +   A  b bbar quark pair

Galaxy = SUPER-B-factory with luminosity some 40 orders of

magnitude above man-made B-factories

basics from cosmology hubble const determines wimp annihilation x section

More precisely by solving Boltzmann eq.

Basics from cosmology:Hubble const. determines WIMP annihilation x-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 annihilation rate  expansion rate,i.e. =<v>n(xfr)  H(xfr) !)

Thermal equilibrium abundance

Actual abundance

Comoving number density

H-Term takes care of decrease in density by expansion. Right-hand side:

annihilation and production.

Jungmann,Kamionkowski, Griest, PR 1995

h2 = mn/c  2.10-27 [cm3/s]/<v>

(<v> independ. of m!)

T=M/22

Present WMAP h2=0.1130.009

requires <v>  2.10-26 cm3/s

x=m/T

DM density increases locally after galaxy formation.

In this room: 1 WIMP/coffee cup 105 averaged density.

slide4

WIMP MASS

50 - 100 GeV

RED=flux from

DM Annihilation

Yellow = backgr.

Blue = BG uncert.

65

0

WIMPS

100

0

IC

WIMPS

IC

Extragal.

Bremsstr.

Extragal.

Bremsstr.

Basics of background and signal shapes

Blue: uncertainty from

WIMP mass

Blue: uncertainty from

background shape

slide5

Quarks

from

WIMPS

Quarks

in protons

Basics of background and signal shapes

No SM

No SM

Protons

Electrons

energy loss times of electrons and nuclei
Energy loss times of electrons and nuclei

t-1

= 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!)

egret on cgro compton gamma ray observ
EGRET on CGRO (Compton Gamma Ray Observ.)

9 yrs of data taken (1991-2000)

Main purpose: sky map of point

sources above diffuse BG.

slide8

Basics of astro-particle physics

Gamma Ray Flux from WIMP annihilation in given direction ψ:

Similar expressions for:

pp->0+x->+x, ( given by gas density, highest in disc)

e->e, eN->eN, ( given by electron/gamma density, highest in disc)

Extragalactic Background (isotropic)

DM annihilation ( 1/r2 for flat rotation curve)

All have very different, but known energy spectra.

Cross sections known. Densities not well known, so keep absolute

normalization free for each process.

Fit shape of various contributions with free normalization, but normalization

limited by experimental overall normalization error, which is 15% for EGRET

data. Point-to-point errors  7% (yields good 2).

slide9

Observed

Profile

z

Rotation Curve

x

y

1/r2 halo

totalDM

disk

2003, Ibata et al, Yanny et al.

bulge

Inner Ring

Outer Ring

Executive Summary for fits in 360 sky directions

Expected

Profile

xy

v2M/r=cons.

and

M/r3

1/r2

for const.

rotation

curve

Divergent for

r=0?

NFW1/r

Isotherm const.

xz

Halo profile

slide10

Excess of Diffuse Gamma Rays above 1 GeV

(first publications by Hunter et al, Sreekumar et al. (1997)

B

C

A

2004

Inv. Compton

0

Bremsstrahlung

Strong, Moskalenko, Reimer, APJ.613, astro-ph/0406254

D

E

F

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)

slide11

Excess of Diffuse Gamma Rays has same spectrum in all

directions compatible with WIMP mass of 50-100 GeV

Egret Excess above

extrapolated background

from data below 0.5 GeV

Statistical

errors only

Excess same shape in all regions

implying same source everywhere

Important: if experiment measures gamma rays down to 0.1 GeV, then normalizations of DM annihilation and background can both be left free, so one is not sensitive to abso- lute background estimates, BUT ONLY TO THE SHAPE, which is much better known.

slide12

Diffuse Gamma Rays for different sky regions

Good Fits for WIMP masses between 50 and 100 GeV

A: inner Galaxy

B: outer disc

C: outer Galaxy

E: intermediate lat.

F: galactic poles

D: low latitude

3 components: galactic background + extragalactic bg + DM annihilation fitted

simultaneously with same WIMP mass and DM normalization in all directions.

Boost factor around 70 in all directions and statistical significance > 10 !

slide13

Optimized Model from Strong et al. astro-ph/0406254

Change spectral shape of electrons AND protons

slide14

Optimized Model from Strong et al. astro-ph/0406254

Change spectral shape of electrons AND protons

Protons

Electrons

Nucleon and electron spectra

tuned to fit gamma ray data.

Apart from the difficulty to

have inhomogeneous nuclei spectra

(SMALL energy losses!) the model

does NOT describe the spectrum

IN ALL DIRECTIONS!

B/C

slide15

Optimized Model from Strong et al. astro-ph/0406254

Change spectral shape of electrons AND protons

300 MeV

150 MeV

100 MeV

500 MeV

1000

MeV

2000

MeV

slide16

Probability of

optimized model

if 2 measured

in 360 sky directions

and integrate data with E>0.5 GeV:

2= 962.3/324 for

Optimized Model

without DM

+correl. errors:

Prob = < 10-10

2= 306.5/323 for

Optimized Model

+DM

+correl. errors:

Prob = 0.736

Boostfactor=25 for OM

vs 70 for CM

Optimized Model from Strong et al. astro-ph/0406254

Change spectral shape of electrons AND protons

slide17

Determining halo profile

DM Gamma Ray Flux:

=2

 1/r2

2 Gaussian ovals

slide18

H

H2

4

R [kpc]

Fit results of halo parameters

Enhancement of rings over 1/r2

profile 2 and 7, respectively.

Mass in rings

1.6 and 0.3%

of total DM

(<v> from WMAP)

Parameter values:

14 kpc coincides with ring

of stars at 14-18 kpc due

to infall of dwarf galaxy

(Yanny, Ibata, …..)

4 kpc coincides with ring of

neutral hydrogen molecules!

Boostfactor  20-200

Dokuchaev et al: 10<B<200, IDM2004

slide19

Halo density on scale of 300 kpc

Sideview

Topview

Cored isothermal profile with scale 4 kpc

Total mass: 3.1012 solar masses

slide21

WITH 2 rings

WITHOUT rings

100<b<200

DISC

100<b<200

DISC

200<b<900

200<b<900

50<b<100

50<b<100

Longitude fits for 1/r2 profile with/w.o. rings

E > 0.5 GeV

Halo parameters from fit to 180 sky directions: 4 long. profiles for

latitudes <50, 50<b<100, 100<b<200, 200<b<900 (=4x45=180 directions)

slide22

Longitude on linear scale

ABOVE 0.5 GeV

BELOW 0.5 GeV

slide25

Normalization

of background:

Compare with GALPROP,

which gives absolute

prediction of background

from gas distributions etc.

slide26

Background scaling factors

Background scaling factor = Data between 0.1 and 0.5 GeV/GALPROP

GALPROP = computer code simulating our galaxy (Moskalenko, Strong)

slide27

Normalization

of DMA ->

“Boost factor”

(= enhancement of DMA

by clustering of DM)

slide28

Clustering of DM -> boosts annih. rate

Annihilation DM density squared!

Clustersize: 1014 cm =10x solar system

Mmin 10-8 -10-6 Mסּ

Cluster density  25 pc-3

Halo mass fraction in clumps: 0.002

From Berezinsky, Dokuchaev, Eroshenko

Boost factor  <2>/<>2  20-200

Clumps with Mmin give the dominant

contribution to DM annihilation ->

many in a given direction -> similar boost factor in all directions

slide29

What about

Supersymmetry?

Assume mSUGRA

5 parameters: m0, m1/2, tanb, A, sign μ

annihilation cross sections in m 0 m 1 2 plane 0 a 0 0

t t

t t

bb

bb

Annihilation cross sectionsin m0-m1/2 plane (μ > 0, A0=0)

tan=5

tan=50

10-24

10-27

EGRET

WMAP





WW

WW

For WMAP x-section of <v>2.10-26 cm3/s one needs large tanβ

slide31

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>=1026 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. CONCLUSION: EGRET data excludes largely coannih.

slide32

Stau coannihilation

mA resonance

WMAP

EGRET

EGRET excess interpreted as DM consistent with

WMAP, Supergravity and electroweak constraints

MSUGRA can fulfill

all constraints from WMAP,

LEP, b->s, g-2 and EGRET

simultaneously, if DM is

neutralino with mass

in range 50-100 GeV and

squarks and sleptons are

O(1 TeV)

Stau

LSP

Incomp. with

EGRET data

No

EWSB

Bulk

slide33

SUSY Mass spectra in mSUGRA

compatible with WMAP AND EGRET

Charginos, neutralinos

and gluinos light

LSP largely Bino  DM is supersymmetric partner of CMB

slide34

Unification of gauge couplings

SM

SUSY

Update from Amaldi, dB,

Fürstenau, PLB 260 1991

With SUSY spectrum from EGRET data and start values of couplings from final LEP data perfect gauge coupling unification possible

comparison with direct dm searches

DAMA

ZEPLIN

Edelweiss

CDMS

Projections

Comparison with direct DM Searches

Spin-dependent

Spin-independent

Predictions from EGRET data assuming Supersymmetry

slide36

Positron fraction and antiprotons

from present balloon exp.

Signal

Signal

Background

Background

Positrons

Positrons

Antiprotons

Antiprotons

SAME Halo and WIMP parameters as for GAMMA RAYS but fluxes dependent on propagation! DMA can be used to tune models:

at present no convection, nor anisotropic diffusion in spiral arms.

slide37

Summary

EGRET excess shows all key features from DM annihilation:

Excess has same shape in all sky directions: everywhere it is

perfectly (only?) explainable with superposition of

background AND mono-energetic quarks of 50-100 GeV

Results and x-sect. in agreement with SUPERSYMMETRY

Excess follows expectations from galaxy formation:

1/r2 profile with substructure,

visible matter/DM0.02

Excess connected to MASS, since it can explain

peculiar shape of rotation curve

These combined features provide FIRST (>10) EVIDENCE that DM is not so dark and follow ALL DMA expectations imagined so far.

Conventional models CANNOT explain above points SIMULTANEOUSLY,

especially spectrum of gamma rays in all directions, DM density profile,

shape of rotation curve, stability of ring of stars at 14 kpc,..