1. SUSY WIMP and Collider Signatures
SuperWIMP Dark Matter (II)
SUSY WIMP and Collider Signatures
Shufang Su • U. of Arizona
J. Feng, F. Takayama, S. Su
Work in progress…

2. WIMP  SWIMP + SM particle-
Takayama’s talk
FRT hep-ph/ ,
WIMP
104 s  t  108 s
SWIMP SM
Gravitino LSP
LKK graviton
106
S. Su SWIMP

3. SWIMP and SUSY WIMP SWIMP: G (LSP) WIMP: NLSP mG» mNLSP ~ SUSY case-
SWIMP: G (LSP) WIMP: NLSP mG» mNLSP ~
SUSY case
Ellis et. al., hep-ph/
104 s  t  108 s
NLSP  G + SM particles ~
Neutralino/Chargino NLSP
Slepton NLSP
BBN EM
had
Brhad  O(0.01)
Brhad  O(10-3)
S. Su SWIMP

4. Slepton NLSP lifetime -
When does it decay ?
l  G + l ~
S. Su SWIMP

5. Slepton NLSP hadronic decay-
l  G + l0+ Z/W ~
How much hadronic energy released ?
had » ml-mG ~
Brhad
Brhad  ~ R
YNLSP
S. Su SWIMP

6. BBN Constraints on Hadronic Injection-
hadBrhadYNLSP 
(2 £ – 4£ ) GeV
Yanagida, talk at DESY, 2003
(prelimenary)
BrhadYNLSP  (2-6) £ 10-15
Dimopoulos et. al.,
NPB 311, 699 (1989)
Need updated analyses of
BBN constraints on
hadronic /EM injection
S. Su SWIMP

7. Favored Mass Region ~ ~ R  SWIMP h2=0.23 500 GeV  mR not favored-
SWIMP h2=0.23
500 GeV  mR ~
not favored
by BBN had  ~ R ~
had
not favored
by BBN EM
 m  GeV
BrhadYNLSP  (2-6) £ 10-15
hadBrhadYNLSP  (2 £ – 4£ ) GeV
S. Su SWIMP

8. Collider Phenomenology
Choudhury et. al., PRD 68, (2003)
Drell-Yang
WBF lL ~ lR -
SWIMP Dark Matter
no signals in direct / indirect dark matter searches
SUSY slepton NLSP: rich collider phenomenology
Baer, Harris and Reno, PRD 57, 5871 (1998)
Slepton NLSP production
Tevatron/LHC: Drell-Yang
LHC: WBF
LC:
m  Ecm/2
study nature of NLSP
distinguish DM scenario
precise measurement of sparticle mass and couplings
S. Su SWIMP

9. Distinguish from stau NLSP and gravitino LSP in GMSB
Charged Slepton NLSP -
Slepton NLSP: stable inside the detector
Charged slepton highly ionizing track, almost background free
charged track in tracking chamber, hit muon detector
little hadronic activities in calorimeters
slow moving: large dE/dx, TOF information
Collider searches:
RUN I and Run II search for highly ionizing particle
LEP searches for stable stau in GMSB
m  99 GeV at 95% C.L.
prospect at Tevatron RUN II
110/180/230 GeV for L=2, 10, 30 fb event
LHC
Cerutti et. al., LEPSUSYWG/
Feng and Moroi, PRD 58, (1998)
cover m » 90 – 700 GeV for L=100 fb-1 (GMSB)
Acosta, talk at HCP2002
Distinguish from stau NLSP and gravitino LSP in GMSB
S. Su SWIMP

10. Sneutrino NLSP Sneutrino NLSP missing energy-
Sneutrino NLSP missing energy
Signal: energetic jets/leptons + missing energy
Is it a sneutrino NLSP in SWIMP scenario
or neutralino LSP in usual SUSY WIMP scenario?
angular distribution of events (LC)
direct/indirect dark matter searches (cosmo)
Collider searches:
invisible Z decay width
m  44.6 GeV at 95% C.L.
detail study for metastable sneutrino NLSP is needed
Hebbeker, PLB 470, 259 (1999)
S. Su SWIMP

11. Conclusions SWIMP is possible candidate for dark matter-
SWIMP 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 SWIMPh2<0.23)
Sneutrino:  m  GeV, m  100 GeV
Charged R: 500 GeV  mR
Rich collider phenomenology
Charged slepton: highly ionizing track
distinguish from metastable stau in GMSB
Sneutrino: missing energy
distinguish from usual neutralino LSP case ~ ~ ~
S. Su SWIMP