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Gravitino Dark matter. the darkest dark matter. Coupling / 1/m pl no signal for direct/indirect DM searches can not be produced at colliders. Shufang Su • U. of Arizona Aspen Winter Conference 2005. New proposal: superWIMP DM. not very exciting. naturally obtain
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Gravitino Dark matter the darkest dark matter • Coupling / 1/mpl • no signal for direct/indirect DM searches • can not be produced at colliders Shufang Su • U. of Arizona Aspen Winter Conference 2005 New proposal: superWIMP DM not very exciting • naturally obtain • solve BBN 7Li anomaly • Could be tested at colliders
mG » mSUSY » GeV – TeV cold Dark Matter ~ mG¿ mSUSY » keV warm Dark Matter ~ Gravitino - • Gravitino: superpartner of graviton • Obtain mass when SUSY is spontaneously broken mG» F/mpl • Stable when it is LSP - candidate of Dark Matter ~ Gravitino Dark Matter
mG» keV :warm Dark Matter • mG keV :problematic ! gravitino dilution necessary stringent bounds on reheating temp. ~ ~ h2» (mG/keV) (100/g*) ~ Gravitino: warm dark matter - mG ¿ mSUSY (GMSB) ~ Moroi, Murayama and Yamaguchi, PLB303, 289 (1993) Gravitino Dark Matter
~ mG » mSUSY» GeV – TeV (supergravity) ~ ~ ~ ~ , , l l LSP LSP • vtoo small • thG too big overclose the Universe unless TRH 1010 GeV ~ ~ ~ G LSP + SM BBN constraints: TRH 105 – 108 GeV Conflict with thermal leptogenesis: TRH 3 £ 109 GeV ~ G G Gravitino cold dark matter - superWIMP DM thermalLSP v-1 (weak coupling)-2 thermalLSP v-1 (gravitational coupling)-2 WIMP Kawasaki, Kohri and Moroi, asrtro-ph/0402490, astro-ph/0408426 Bolz, Brandenburg and Buchmuller, NPB 606, 518 (2001) Buchmuller, Bari, Plumacher, NPB665, 445 (2003) Gravitino Dark Matter
WIMP SWIMP + SM particle - FRT hep-ph/0302215, 0306024 WIMP 104 s t 108 s SWIMP SM Gravitino LSP LKK graviton 106 Gravitino Dark Matter
~ SWIMP: G (LSP) WIMP: NLSP mG» mNLSP ~ NLSP G + SM particles SuperWIMP and SUSY WIMP - • SUSY case ~ Ellis et. al., hep-ph/0312262; Wang and Yang, hep-ph/0405186. 104 s t 108 s Gravitino Dark Matter
/10-10 = 6.1 0.4 Dark matter density G· 0.23 ~ Fields, Sarkar, PDG (2002) Constraints - ~ NLSP G + SM particles SWIMP=(mSWIMP/mNLSP) thNLSP CMB photon energy distribution Big bang nucleosynthesis Late time EM/had injection could change the BBN prediction of light elements abundances Gravitino Dark Matter
~ had EM EM (GeV) EM » mNLSP-mG Cyburt, Ellis, Fields and Olive, PRD 67, 103521 (2003) Kawasaki, Kohri and Moroi, astro-ph/0402490 BBN constraints on EM/had injection - • Decay lifetime NLSP • EM/had energy release around a year EM,had=EM,had BrEM,had YNLSP Gravitino Dark Matter
G = (mG/mNLSP) thNLSP ~ ~ NLSP, EM,had=EM,had BEM,had YNLSP apply CMB and BBN constraints on (NLSP, EM/had) viable parameter space sleptonand sneutrino NLSP - J. Feng, F. Takayama, S. Su hep-ph/0404198, 0404231 Gravitino Dark Matter
BBN EM constraints only Stau NLSP superWIMP in mSUGRA - Ellis et. al., hep-ph/0312262 Usual WIMP allowed region superWIMP allowed region Gravitino Dark Matter
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: gravitinom » keVwarm not cold DM • collider searches:other sparticle (mass) • (GMSB) ¿(SWIMP):distinguish experimentally Feng and Smith, in preparation. Gravitino Dark Matter
Guaranteed signal at colliders Feng, SS, Takayama, in preparation - Model independent approach: DM < v>ann production Birkedal, matchev, Perelstein, PRD 70, 077701 (2004). • Usual WIMP:missing energy + jet or photon irreducible SM background • superWIMP:promising event rates at LHC/LC. preliminary preliminary Gravitino Dark Matter
Sneutrino and neutralino NLSP vs. , 0.23 favor gravitino LSP ~ ~ - • 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) 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, ~ ~ Gravitino Dark Matter
Decay life time • SM particle energy/angular distribution … mG mpl LFV … ~ ~ ~ ~ ~ ~ G G G G G SM NLSP NLSP SM NLSP SM NLSP SM Buchmuller et. al., hep-ph/0402179 Hamaguchi and Ibarra, hep-ph/0412229 Feng et. al., Hep-ph/0405248 SM NLSP Slepton trapping: Hamaguchi et. al. hep-ph/0409248 Feng and Smith, hep-ph/0409278 Gravitino Dark Matter
Slepton trapping Feng and Smith, hep-ph/0409278 - • 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 are 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 Gravitino Dark Matter Courtesy of J. Feng
Conclusions - • Gravitino could be warm DM: m » keV • Gravitino could be cold DM: m » few hundred GeV • thermal production: TRH 1010 GeV • Non-thermal production: superWIMP SuperWIMP:gravitino LSP WIMP:slepton/sneutrino/neutralino • Constraints from BBN: EM injection and hadronic injection viable parameter space • Rich collider phenomenology(no direct/indirect DM signal) • charged slepton:highly ionizing track • sneutrino/neutralino:missing energy • Slepton trapping WIMP superWIMP + SM particle Gravitino Dark Matter