Shufang Su • U. of Arizona superWIMP Dark matter the darkest dark matter Coupling / 1/mpl (very suppressed) no signal for direct/indirect DM searches can not be produced at colliders Shufang Su • U. of Arizona not very exciting naturally obtain  solve BBN 7Li anomaly could be tested at colliders Work collaborated with J. Feng, F. Takayama

Outline WIMP and superWIMP dark matter Gravitino LSP as superWIMP - WIMP and superWIMP dark matter Gravitino LSP as superWIMP 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 Slepton trapping Conclusion S. Su SWIMP

Dark Matter (DM) DM h2=0.112 § 0.009 Non-baryonic Stable Neutral Cold Can not be any of the known particles  microscopic identity of DM ? WIMP and superWIMP appear in particle physics models motivated independently by attempts to solve EWSB relic density are determined by Mpl and Mweak naturally around the observed value no need to introduce and adjust new energy scale S. Su SWIMP

Universe cools: n=nEQe-m/T WIMP - Thermal equilibrium  $ ff Boltzmann equation expansion   ff ff   Universe cools: n=nEQe-m/T WIMP =n hvi v.s. H WIMP » h anv i-1 mWIMP» Mweak an » weak2 Mweak-2 naturally around the observed value e.g. neutralino LSP Freeze out, n/s » const early time   H n ¼ neq late time   H (n/s)today » (n/s)decoupling at freeze-out ¼ H TF » m/25 Approximately, relic / 1/hvi S. Su SWIMP

superWIMP WIMP  superWIMP + SM particles 104 s  t  108 s SM - WIMP  superWIMP + SM particles FRT hep-ph/0302215, 0306024 104 s  t  108 s SWIMP WIMP SM superWIMP e.g. Gravitino LSP LKK graviton WIMP neutral charged 106 S. Su SWIMP

Gravitino Gravitino: superpartner of graviton - Gravitino: superpartner of graviton Obtain mass when SUSY is spontaneously broken mG » F/mpl Stable when it is LSP - candidate of Dark Matter ~ mG ¿ mSUSY » keV warm Dark Matter ~ mG » mSUSY » GeV – TeV cold Dark Matter ~ S. Su SWIMP

Gravitino: warm dark matter - mG ¿ mSUSY (GMSB) ~ ~  h2 » (mG/keV) (100/g*) mG » keV : warm Dark Matter mG  keV : problematic ! gravitino dilution necessary  stringent bounds on reheating temp. ~ Moroi, Murayama and Yamaguchi, PLB303, 289 (1993) S. Su SWIMP

Gravitino cold dark matter - mG » mSUSY » GeV – TeV (supergravity) ~ G ~ , l LSP G ~ , l LSP superWIMP DM thermalLSP  v-1  (weak coupling)-2 thermalLSP  v-1  (gravitational coupling)-2 WIMP G  LSP + SM BBN constraints: TRH  105 – 108 GeV Conflict with thermal leptogenesis: TRH  3 £ 109 GeV ~ v too small thG too big overclose the Universe unless TRH  1010 GeV ~ Kawasaki, Kohri and Moroi, asrtro-ph/0402490, astro-ph/0408426 Bolz, Brandenburg and Buchmuller,NPB 606, 518 (2001) Buchmuller, Bari, Plumacher, NPB665, 445 (2003)

Superpartner of graviton superWIMP : an example - change light element abundance predicted by BBN Strong constraints ! SUSY case WIMP  superWIMP + SM particles NLSP: slepton/sneutrino neutralino/chargino Gravitino LSP Superpartner of graviton WIMP superWIMP SM particle » 1 mpl2 Decay lifetime  planck mass S. Su SWIMP

superWIMP and SUSY WIMP - 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

superWIMP in mSUGRA Usual WIMP allowed region superWIMP allowed region - BBN EM constraints only Stau NLSP Ellis et. al., hep-ph/0312262 Usual WIMP allowed region superWIMP allowed region 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 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

SM particle energy/angular distribution …  mG Decay life time SM particle energy/angular distribution …  mG  mpl … ~ SM NLSP Probes gravity in a particle physics experiments! BBN, CMB in the lab Precise test of supergravity: gravitino is a graviton partner ~ G SM NLSP SM NLSP ~ G ~ G SM NLSP SM NLSP ~ G ~ G How to trap slepton? Hamaguchi, kuno, Nakaya, Nojiri, hep-ph/0409248 Feng and Smith, hep-ph/0409278 S. Su SWIMP

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. Catch 100/yr in 1 kton water LC: tune beam energy to produce slow sleptons, can catch 1000/yr in 1 kton water 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 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 sneutrino/neutralino: missing energy slepton trapping WIMP  superWIMP + SM particle ~ ~ ~ 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