Shufang Su • U. 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 is the gravitino not usually considered as DM? - In supergravity, for mG » GeV – TeV ~ 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

Outline SWIMP dark matter and gravitino LSP Constraints - 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 S. Su SWIMP

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

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/0312262; Wang and Yang, hep-ph/0405186. 104 s  t  108 s NLSP  G + SM particles ~ neutralino/chargino NLSP slepton/sneutrino NLSP BBN EM had Brhad  O(0.01) Brhad  O(10-3) S. Su SWIMP

Constraints ~ NLSP  G + SM particles  Dark matter density G · 0.23 - ~ NLSP  G + SM particles  Dark matter density G · 0.23 ~ Approach I Approach II SWIMP close universe SWIMP maybe insiginificant nNLSP  SWIMP/mSWIMP1/mSWIMP  1/mSUSY thNLSP  v-1  m2SUSY  nNLSP  mSUSY NLSP: slepton,sneutrino neutralino : excluded NLSP: slepton, sneutrino, neutralino fix G = 0.23 ~ G = mG/mNLSP thNLSP ~ S. Su SWIMP

Constraints (cont’)  CMB photon energy distribution -  CMB photon energy distribution - early decay:  = 0 thermalized through e  e, eX  eX , e  e - late decay:   0 statistical but not thermodynamical equilibrium || · 9 £ 10-5 Fixsen et. al., astro-ph/9605054 Hagiwara et. al., PDG S. Su SWIMP

Constraints (cont’) ?  Big bang nucleosynthesis /10-10 = 6.1 0.4 Fields, Sarkar, PDG (2002) S. Su SWIMP

BBN constraints on EM/had injection - Decay lifetime NLSP EM/had energy release EM,had=EM,had BrEM,had YNLSP Cyburt, Ellis, Fields and Olive, PRD 67, 103521 (2003) EM EM (GeV) » mNLSP-mG ~ Kawasaki, Kohri and Moroi, astro-ph/0402490 had EM S. Su SWIMP

Decay lifetime Decay lifetime (sec) ~ ~ l  G + l,  ! G +  - Decay lifetime (sec) l  G + l,  ! G +  ~ B  G + /Z/h ~ S. Su SWIMP

EM.had and BrEM, had EM, had » mNLSP-mG EM/had branching ratio BrEM, had ~ neutralino slepton Sneutrino EM mode BrEM 1 had Brhad O(1) O(10-2 - 10-6) S. Su SWIMP

YNLSP: approach I approach I: fix G = 0.23 ~ slepton and sneutrino - approach I: fix G = 0.23 ~ slepton and sneutrino 200 GeV ·  m · 400 » 1500 GeV mG ¸ 200 GeV ~  m · 80 » 300 GeV apply CMB and BBN constraints on (NLSP, EM/had )  viable parameter space NLSP, EM,had=EM,had BEM,had YNLSP S. Su SWIMP

YNLSP: approach II approach II: G = (mG/mNLSP) thNLSP ~ - approach II: G = (mG/mNLSP) thNLSP ~ Approximately right-handed slepton sneutrino (left-handed slepton) neutralino “bulk” -“focus point/co-annihilation” S. Su SWIMP

Approach II: slepton and sneutrino - G = (mG/mNLSP) thNLSP ~ S. Su SWIMP

Approach II: bino - G = (mG/mNLSP) thNLSP ~ S. Su SWIMP

Distinguish from stau NLSP and gravitino LSP in GMSB 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. S. Su SWIMP

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 ~ S. Su SWIMP

Conclusions SuperWIMP is possible candidate for dark matter - 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? ~ ~ ~ S. Su SWIMP

SM energy distribution  Mpl Decay life time SM energy distribution  Mpl  mG  SUSY breaking scale ~ SM NLSP ~ G NLSP SM SM NLSP ~ G Capture particle: Goity, Kossler and Sher, hep-ph/9305244 ~ G SM NLSP NLSP SM ~ G Supergravity at colliders Buchmuller et. al. hep-ph/0402179 ~ G SWIMPs and slepton traps Feng and Smith In preparation… S. Su SWIMP

Slepton trapping (from J. Feng) - Slepton could live for a year, so can be trapped then moved to a quiet environment to observe decays LHC: 106 slepton/yr possible, but most a fast. By optimizing trap location and shape, can catch » 100/yr in 1000m3 water LC: tune beam energy to produce slow sleptons, can catch 1000/yr in 1000m3 water Courtesy of J. Feng S. Su SWIMP

Frequently asked question

Something about  lepton -   G +, ~   mesons, induce hadronic cascade meson decay before interact with BG hadrons longer than typical meson (, K) lifetime (E/m)£ 10-8 s S. Su SWIMP