E6.2 - Direct Detection of Dark Matter

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E6.2 - Direct Detection of Dark Matter
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E6.2 - Direct Detection of Dark Matter

• WIMP - massive Dark Matter particle, weak
  interaction cross section s
• s enables dark/luminous matter balance
• SUSY broken at weak scale provides attractive
  candidate - LSP (Neutralino, ?)
• Favored SUSY models have no definitive floor on
  ?-nucleon scattering cross section s
• s ?10-46 cm2 (10-10 picobarn) significant
• tiny s strong amplitudes cancel when does
  that ever happen?

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Cross Sections (?- nucleon)
Experiment (CDMS, DAMA, Edelweiss)
Various SUSY Models
10-10 pb
? or
http//dmtools.berkeley.edu (Gaitskell/Mandic)
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Some Key Variables

• Mass - converted to kg Germanium, assuming
  coherence
• Time ?B between background events in years, for 1
  kg and for a bin width in energy deposition of 1
  keV.
• Experiments usually run until background limited
  region shown on the plot...
• Plot ?B v. Mass to see progression from 10-6 pb
  sensitivity (now) to 10-10 pb

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WIMP Detectors
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Wimp Detectors - Blossoming
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E6.2 - Direct Detection of Dark Matter

• Axion - light p 0, couples to ??, inhibits CP
  violation in QCD (neutron EDM)
• ?? coupling constant gA??? mA
• Floor on the proportionality constant
• Attractive dark matter candidate when mass of
  axion mA, 10-6 eV lt mA lt 10-2 eV

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Axion Searches
Rosenberg/Kinion Axion Collaboration (Microwave
Cavity)