Transcript ASBS2 - University of Arizona

SuperWIMP Dark matter
Gravitino from Slepton and Sneutrino Decays
Shufang Su • U. of Arizona
J. Feng, F. Takayama, S. Su
Hep-ph/0404198
Outline
SWIMP dark matter and gravitino LSP
Late time energy injection and BBN
Slepton and sneutrino NLSP
~
– Dominant two body EM decay l ! l+G
– Subdominant 3-body hadronic decay
– Viable parameter space
Conclusion
S. Su SWIMP
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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
106
S. Su SWIMP
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SWIMP and SUSY WIMP
 SUSY case
~ (LSP)
SWIMP: G
WIMP: NLSP mG~» mNLSP
Ellis et. al., hep-ph/0312262
104 s  t  108 s
~
NLSP  G + SM particles
Neutralino/Chargino NLSP Slepton NLSP
EM
BBN
had
Brhad  O(0.01)
S. Su SWIMP
Brhad  O(10-3)
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Different approach to gravitino superWIMP
~
NLSP  G + SM particles
my talk
fix SWIMP = 0.23
Takayama’s talk
SWIMP = m~G/mNLSP 
th
NLSP
SWIMP close universe
SWIMP maybe insiginificant
nNLSP  NLSP/mNLSP 
1/mSUSY
thNLSP  v-1  m2SUSY
 nNLSP  mSUSY
NLSP: slepton,sneutrino
NLSP: slepton, sneutrino,
neutralino
S. Su SWIMP
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Late time energy injection and BBN
/10-10 = 6.1 0.4
EM, had energy injection:
?
EM,had=EM,had BEM,had YNLSP
» mNLSP-mG
Fields, Sarkar, PDG (2002)
S. Su SWIMP
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EM and Had BBN constraints
EM BBN constraints
Cyburt, Ellis, Fields and Olive,
PRD 67, 103521 (2003)
S. Su SWIMP
had BBN constraints
EM BBN
Kawasaki, Kohri and Moroi,
astro-ph/0402490
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Slepton NLSP lifetime and EM injection
~
~
~
l  G + l, ~ ! G + 
Decay lifetime (sec)
S. Su SWIMP
EM energy injection EM (GeV)
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Hadronic decay branching ratio
~
~
~
~
~
l  lZG,WG , ~
 ! ZG, lWG
meson contribution
mNLSP
S. Su SWIMP
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Viable Parameter space
200 GeV ·  m · 400 » 1500 GeV
mG~ ¸ 200 GeV
 m · 80 » 300 GeV
negligible EM BBN constraints
S. Su SWIMP
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Conclusions
SuperWIMP is possible candidate for dark matter
SUSY models: gravitino LSP (SWIMP) slepton NLSP (WIMP)
Constraints from BBN: EM injection and hadronic injection
need updated studies of BBN constraints on hadronic/EM injection
Favored mass region: (enlarged if SWIMP<0.23)
~~
 Sneutrino:  m  80-300 GeV  m
  100 GeV
 Charged ~R: 200 GeV ·  m · 1500 GeV, mG ¸~ 200 GeV
 500 GeV  m~R
Rich collider phenomenology (no direct/indirect DM signal)
 Charged slepton: highly ionizing track
 Sneutrino: missing energy
S. Su SWIMP
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● Decay life time  mpl
● SM energy distribution
SM
NLSP
~
G
SM
NLSP

~
G
~
G
SM
NLSP
SM
NLSP
~
G
S. Su SWIMP
SM
NLSP
m~G
 SUSY breaking scale
~
G
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