A Comparison Between Direct and Indirect Dark Matter Search

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A Comparison Between Direct and Indirect Dark
Matter Search


Carlos Muñoz
Madrid Autónoma University Institute for
Theoretical Physics
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• Direct Detection of Neutralino Dark Matter in
  Supergravity
• S. Baek, D.G. Cerdeño, Y.G. Kim, P. Ko, C.M.
• Gamma-Ray Detection from Neutralino Annihilation
  in Non-Universal SUGRA Scenarios
• Y. Mambrini, C.M.
• Adiabatic Compression and Indirect Detection
  of Supersymmetric Dark Matter
• Y. Mambrini, C.M., E. Nezri, F. Prada
• A comparison between direct and indirect dark
  matter search
• Y. Mambrini, C.M.

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OUTLINE

• A natural candidate for dark matter is a Weakly
  Interacting Massive Particle

• A natural candidate for WIMP is a supersymmetric
  particle
• The
  Neutralino

• In principle, detecting WIMPs by experiments on
  the Earth, or on satellites, is possible

• DIRECT DETECTION
• Elastic scattering with nuclei in a material
• Experiments in underground laboratories

• INDIRECT DETECTION
• Through gamma rays from annihilation products in
  the galactic center
• Space-based detectors

Which kind of experiments, direct or indirect
detection, will be able to test larger regions of
the parameter space of supersymmetric models ?
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DIRECT DETECTION
Supersymmetry
Working in the framework of Supergravity

• One can assume universal soft terms Ma M , ma
  m , Aabg A

• The RGEs are used to derive the low-energy soft
  parameters

With MGUT ? 2 1016 GeV, m2Hu evolves towards
large and negative values
µ2 ? - m2Hu - (1/2)M2Z is large
m2H ? mA ? m2Hd - m2Hu -M2Z is large
Small cross section
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sc10-n lt 310-8 pb
More sensitive detectors producing further data
are needed
Experimental constraints -- masses of the
Higgs and superpartners, e.g. mh gt114 GeV -- low
energy observables (BR(b s?), BR(Bs
µ µ- ), g-2)
Astrophysical constraints --Relic density
0.1ltWDM h2lt0.3, WMAP range 0.094ltWDM
h2lt0.129
In addition, the parameter space may be limited
by Charge and Colour Breaking constraints
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m2Hu m2 (1du ) , m2Hd m2 (1dd)
Departures from universality can lead to an
increase of the predictions for sc10-n

• du gt 0

• dd lt 0

µ2 ? - m2Hu - (1/2)M2Z is smaller
m2H ? m2A ? m2Hd - m2Hu - M2Z is smaller Thus
sc10-n is increased
M1M , M2M (1d2) , M3M (1d3)
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tan ? 35
tan ? 25
Summary

• Neutralinos with masses ? (10-400) GeV can be
  obtained within the reach of detectors

CDMS Soudan, sc10-n ? 10-7,-8 pb, will cover a
small part of the parameter space
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INDIRECT DETECTION

• Annihilation of WIMPs in the galactic center
  will produce gamma rays

and these can be measured in space-based
detectors
EGRET telescope, after 5 years of mapping the
gamma-ray sky, identified a gamma-ray source at
the galactic center that, apparently, has no
simple explanation with standard processes. In
particular, the flux is
about 10-8 cm-2 s-1
The Compton Gamma Ray Observatory (CGRO) satellite
Starting in 2007, the GLAST satellite will be
able to detect a flux of gamma rays, as small as
10-11 cm-2 s-1 , clarifying the situation
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As in the case of direct detection, it is also
crucial for indirect detection to analyze the
compatibility of the neutralino as a dark matter
candidate, with the sensitivity of detectors
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Theoretical Predictions
? (?line of sight r2 dr) sann v /m2
Particle physics
Astrophysics
Particle physics Since the diagrams are
related, we can use the same arguments as for
direct detection
Astrophysics e.g. a NFW profile for our galaxy,
has for small distances from the galactic center
r(r) r0/r
E.g. for r 10-5 kpc, r(r) r0 x
106
For m 100 GeV and WDM h2 1/sann 0.1 this
implies the upper bound
? 10-9 cm-2 s-1 i.e. below EGRET
sensitivity
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However GLAST will be able to test some regions
tan ? 35
Which kind of experiments, direct or indirect
detection, will be able to test larger regions of
the parameter space of supersymmetric models ?
EDELWEISS II

GLAST
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EDELWEISS II

GLAST
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Baryons

• The previous situation occurs for simulations
  of halos without baryons. When baryons are taken
  into account a larger r(r) is obtain, producing a
  larger ?

a NFW profile including baryons has r(r)
r0/r1.45 , producing ? x 100
Equivalent to Moore et al. profile without baryons
EGRET
The combination of both effects, non-universality
baryons, may allow to reproduce the observations
0.
0.
0.
Neutralino masses between 150 and 600 GeV
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GLAST
Even for mSUGRA, points corresponding to tan ?5
will be reached by GLAST
Thus, important regions of the parameter space of
SUGRA will be tested by GLAST
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CONCLUSIONS

• There are impressive experimental efforts in
  order to obtain a direct or indirect detection of
  dark matter

• Supersymmetry has an interesting candidate the
  neutralino

We have analyzed the compatibility of the
neutralino as a dark matter candidate, with the
sensitivity of detectors
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• sc10-nucleon in supergravity, with universal
  soft terms, is too small
• Larger sc10-nucleon can be obtained with
  non-universal masses Regions accesible
  for experiments are present

Direct Detection

• Neutralinos with masses ? (10-500) GeV can be
  obtained
• within the reach of dark matter detectors

CDMS Soudan, sc10-n ? 10-7,-8 pb, will cover a
small part of the parameter space

• ?? (c10-c10) in Supergravity with universality
  is in general small
• Larger ? can be obtained with non-universality.
  Actually, using a NFW profile, more regions will
  be accesible than in direct detection

Indirect
Including baryons, GLAST will cover important
regions of the parameter space
THE END