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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/ ,
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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
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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
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WIMP SWIMP + SM particle
- FRT hep-ph/ , WIMP 104 s t 108 s SWIMP SM Gravitino LSP LKK graviton 106 S. Su SWIMP
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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/ ; Wang and Yang, hep-ph/ 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
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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/mSWIMP1/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
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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/ Hagiwara et. al., PDG S. Su SWIMP
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Constraints (cont’) ? Big bang nucleosynthesis /10-10 = 6.1 0.4
Fields, Sarkar, PDG (2002) S. Su SWIMP
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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, (2003) EM EM (GeV) » mNLSP-mG ~ Kawasaki, Kohri and Moroi, astro-ph/ had EM S. Su SWIMP
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Decay lifetime Decay lifetime (sec) ~ ~ l G + l, ! G +
- Decay lifetime (sec) l G + l, ! G + ~ B G + /Z/h ~ S. Su SWIMP
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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( ) S. Su SWIMP
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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
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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
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Approach II: slepton and sneutrino
- G = (mG/mNLSP) thNLSP ~ S. Su SWIMP
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Approach II: bino - G = (mG/mNLSP) thNLSP ~ S. Su SWIMP
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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
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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 ~ S. Su SWIMP
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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
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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/ ~ G SM NLSP NLSP SM ~ G Supergravity at colliders Buchmuller et. al. hep-ph/ ~ G SWIMPs and slepton traps Feng and Smith In preparation… S. Su SWIMP
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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
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Frequently asked question
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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
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