Transcript ASBS2 - University of Arizona

SuperWIMP Dark matter
in SUSY with a Gravitino LSP
Shufang Su • U. of Arizona
J. Feng, F. Takayama, S. Su
hep-ph/0404198, 0404231
Why gravitino not considered as CDM usually?
thG~  v-1  (gravitional coupling)-2
(comparig to WIMP of weak coupling strength)
● v too small
● thG~ too big, overclose the Universe
However, gravitino can get relic density by other means
SuperWIMP
S. Su SWIMP
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WIMP  SWIMP + SM particle
FRT hep-ph/0302215, 0306024
WIMP
104 s  t  108 s
SWIMP
SM
 Gravitino LSP
 LKK graviton
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Outline
SWIMP dark matter and gravitino LSP
Constraints
- Late time energy injection and BBN
NLSP  gravitino +SM particle
slepton, sneutrino, neutralino
- approach I: fix SWIMP=0.23
- approach II: SWIMP=(mSWIMP/mNLSP) thNLSP
Collider phenomenology
Conclusion
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SWIMP and SUSY WIMP
 SUSY case
~ (LSP)
SWIMP: G
WIMP: NLSP mG~ » mNLSP
Ellis et. al., hep-ph/0312262; Wang and Yang, hep-ph/0405186.
104 s  t  108 s
~
NLSP  G + SM particles
neutralino/chargino NLSP
slepton/sneutrino NLSP
Brhad  O(0.01)
Brhad  O(10-3)
EM
BBN
had
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Constraints
~
NLSP  G + SM particles
/10-10 = 6.1 0.4
 Dark matter density G~ · 0.23
 CMB photon energy distribution
|| · 9 £ 10-5
Fixsen et. al., astro-ph/9605054
Hagiwara et. al., PDG
 Big bang nucleosynthesis
Late time EM/had injection could
change the BBN prediction of
light elements abundances
Fields, Sarkar, PDG (2002)
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BBN constraints on EM/had injection
 Decay lifetime NLSP
 EM/had energy release
had
EM
EM (GeV)
had (GeV)
» mNLSP-mG
EM,had=EM,had BrEM,had
YNLSP
EM
Cyburt, Ellis, Fields and Olive, PRD 67, 103521 (2003)
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Kawasaki, Kohri and Moroi, astro-ph/0402490
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YNLSP: approach I
 approach I: fix G~ = 0.23
200 GeV ·  m · 400 » 1500 GeV
, EM,had=EM,had BEM,had
mG~ ¸ 200
GeV
NLSP
slepton and sneutrino
YNLSP
 m · 80 » 300 GeV
apply CMB and BBN constraints on (NLSP, EM/had )
 viable parameter space
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Approach II: right-handed slepton
G~ = (m~G/mNLSP) thNLSP
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Approach II: sneutrino
G~ = (m~G/mNLSP) thNLSP
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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, Murayama 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)
vs.
 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~,~
~,~  0.23  favor gravitino LSP
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Conclusions
SuperWIMP is possible candidate for dark matter
SUSY models
SWIMP: gravitino LSP WIMP: slepton/sneutrino/neutralino
Constraints from BBN: EM injection and hadronic injection
need updated studies of BBN constraints on hadronic/EM injection
Favored mass region
 Approach I: fix ~G=0.23
 Approach II: G~ = (mG~/mNLSP) thNLSP
Rich collider phenomenology (no direct/indirect DM signal)
 charged slepton: highly ionizing track
distinguish from GMSB
 sneutrino/neutralino: missing energy
stable or not?
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● Decay life time  Mpl
● SM energy distribution
SM
NLSP
~
G
SM
NLSP

~
G
~
G
SM
NLSP
SM
NLSP
~
G
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SM
NLSP
m~G
 SUSY breaking scale
~
G
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