SuperWIMP Dark matter

1
SuperWIMP Dark matter
in SUSY with a Gravitino LSP

• Shufang Su U. of Arizona

J. Feng, F. Takayama, S. Su hep-ph/0404198,
0404231
See also, Jonathan Fengs talk, SuperWIMPs and
Slepton Traps
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Why is the gravitino not usually considered as
DM?
-
In supergravity, for mG GeV TeV

However, gravitino can get relic density by
other means SuperWIMP
3
WIMP ? SWIMP SM particle
-
FRT hep-ph/0302215, 0306024
WIMP
104 s ? t ? 108 s
SWIMP
SM

• ? Gravitino LSP
• ? LKK graviton

106
4
Outline
-

• SWIMP dark matter and gravitino LSP
• Constraints
• Late time energy injection and BBN
• NLSP ? gravitino SM particle
• slepton, sneutrino, neutralino
• - approach I fix ?SWIMP0.23
• - approach II ?SWIMP(mSWIMP/mNLSP) ?thNLSP
• Collider phenomenology
• Conclusion

Updates since Jan SLAC LC workshop
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SWIMP and SUSY WIMP
-

• SUSY case

Ellis et. al., hep-ph/0312262 Wang and Yang,
hep-ph/0405186.
104 s ? t ? 108 s
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Constraints
-

NLSP ? G SM particles
- approach I fix ?SWIMP0.23 - approach II
?SWIMP(mSWIMP/mNLSP) ?thNLSP
? CMB photon energy distribution
? Big bang nucleosynthesis
Late time EM/had injection could change the BBN
prediction of light elements abundances
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BBN constraints on EM/had injection
-

• Decay lifetime ?NLSP
• EM/had energy release

?EM,had?EM,had BrEM,had YNLSP
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YNLSP approach I
-
slepton and sneutrino
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Approach II slepton and sneutrino
-
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Collider Phenomenology
-

• SWIMP Dark Matter
• no signals in direct / indirect dark matter
  searches
• SUSY NLSP rich collider phenomenology

NLSP in SWIMP long lifetime ? stable inside the
detector

• Charged slepton highly ionizing track, almost
  background free

Distinguish from stau NLSP and gravitino LSP in
GMSB

• GMSB gravitino m keV warm not cold DM
• collider searches other sparticle (mass)
• ?(GMSB) ?(SWIMP) distinguish experimentally

Feng and Smith, in preparation.
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Sneutrino and neutralino NLSP
-

• sneutrino and neutralino NLSP missing energy
• signal energetic jets/leptons missing energy

? Is the lightest SM superpartner sneutrino or
neutralino?

• angular distribution of events (LC)

? Does it decay into gravitino or not?

• sneutrino case most likely gravitino is LSP
• neutralino case most likely neutralino LSP

• direct/indirect dark matter search
• positive detection ? disfavor gravitino LSP
• precision determination of SUSY parameter
  ?th?,?

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• Decay life time
• SM energy distribution
• ? Mpl
• ? mG
• ? SUSY breaking scale

NLSP
SM
NLSP
SM
NLSP
SM
Capture particle Goity, Kossler and Sher,
hep-ph/9305244
NLSP
SM
NLSP
SM
Supergravity at colliders Buchmuller et. al.
hep-ph/0402179
SWIMPs and slepton traps Feng and Smith In
preparation See Fengs talk
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Conclusions
-

• SuperWIMP is possible candidate for dark matter
• SUSY models
• SWIMP gravitino LSP WIMP slepton/sneutrino/n
  eutralino
• Constraints from BBN EM injection and hadronic
  injection
• need updated studies of BBN constraints on
  hadronic/EM injection
• Favored mass region
• Approach I fix ?G0.23
• Approach II ?G (mG/mNLSP) ?thNLSP
• Rich collider phenomenology (no direct/indirect
  DM signal)
• charged slepton highly ionizing track
• sneutrino/neutralino missing energy
• Other implications