Gravitino Dark matter

Gravitino Dark matterGravitino Dark matter

Shufang Su • U. of ArizonaShufang Su • U. of Arizona

Aspen Winter Conference 2005Aspen Winter Conference 2005

the darkest dark matterthe darkest dark matter

Coupling Coupling // 1/m 1/mplpl

no signal for direct/indirect DM searchesno signal for direct/indirect DM searches can not be produced at colliderscan not be produced at colliders

not very excitingnot very excitingNew proposal: New proposal: superWIMP superWIMP DMDM naturally obtain naturally obtain

solve BBN solve BBN 77Li anomalyLi anomaly Could be tested at collidersCould be tested at colliders

S. Su Gravitino Dark Matter 3

Gravitino Gravitino

Gravitino: superpartner of gravitonGravitino: superpartner of graviton

Obtain mass when SUSY is spontaneously broken Obtain mass when SUSY is spontaneously broken mmGG »» F/m F/mplpl

Stable when it is LSP Stable when it is LSP - candidate of Dark Matter- candidate of Dark Matter

~~

mmG G »» m mSUSYSUSY

»» GeV – TeV GeV – TeV

coldcold Dark Matter Dark Matter

~~mmGG ¿¿ m mSUSYSUSY

» » keVkeV

warmwarm Dark Matter Dark Matter

~~


Gravitino: warm dark matter Gravitino: warm dark matter

mmG G ¿¿ m mSUSYSUSY (GMSB)(GMSB)

~~ hh22 »» (m (mGG/keV) (100/g/keV) (100/g**))

mmGG »» keV : keV : warmwarm Dark Matter Dark Matter

mmGG keV : keV : problematic !problematic !

gravitino dilution necessarygravitino dilution necessary

stringent bounds on reheating temp. stringent bounds on reheating temp.

~~

~~

Moroi, Murayama and Yamaguchi, PLB303, 289 (1993)

~~


Gravitino cold dark matter Gravitino cold dark matter

mmG G »» m mSUSYSUSY »» GeV – TeV GeV – TeV (supergravity)(supergravity)

~~

thermalthermalLSPLSP vv-1-1

((weak weak coupling)coupling)-2-2

GG~~

~~ ll~~ LSPLSP

WIMPWIMP thermalthermalLSPLSP vv-1-1

((gravitational gravitational coupling)coupling)-2-2

GG~~~~ ll

~~LSPLSP

● vv too smalltoo small

● ththGG too big too big

overclose the Universeoverclose the Universe unless Tunless TRHRH 10 101010 GeV GeV

~~

superWIMPsuperWIMPDMDM

G G LSP + SM LSP + SM

BBN constraints:BBN constraints: TTRHRH 10 1055 – 10 – 1088 GeV GeV

Conflict with thermal leptogenesis:Conflict with thermal leptogenesis: TTRHRH 3 3 ££ 10 1099 GeV GeV

~~

Bolz, Brandenburg and Buchmuller,NPB 606, 518 (2001)

Kawasaki, Kohri and Moroi, asrtro-ph/0402490, astro-ph/0408426

Buchmuller, Bari, Plumacher, NPB665, 445 (2003)


WIMPWIMP

SWIMPSWIMPSMSM

101066

WIMP SWIMP + SM particle WIMP SWIMP + SM particle

FRT hep-ph/0302215, 0306024

101044 s s t t 10 1088 s s

Gravitino LSPGravitino LSP

LKK gravitonLKK graviton


SuperWIMP and SUSY WIMP SuperWIMP and SUSY WIMP

SUSY caseSUSY case

NLSP NLSP G + SM particles G + SM particles~~

SWIMP: G (LSP) WIMP: NLSP SWIMP: G (LSP) WIMP: NLSP mmGG »» m mNLSPNLSP~~

nneutralino/eutralino/cchargino hargino NLSPNLSP

ssleptonlepton/sneutrino/sneutrino NLSP NLSP

BBBBNN

EMEM

hahadd

BrBrhadhad O(0.01) O(0.01) BrBrhadhad O(10 O(10-3-3))

101044 s s t t 10 1088 s s

Ellis et. al., hep-ph/0312262; Wang and Yang, hep-ph/0405186.

~~


Constraints Constraints

NLSP NLSP G + SM particles G + SM particles~~

Dark matter density Dark matter density GG ·· 0.23 0.23~~

CMB photon energy distributionCMB photon energy distribution

Big bang nucleosynthesisBig bang nucleosynthesis

Late time EM/had injection could Late time EM/had injection could change the BBN prediction of change the BBN prediction of light elements abundanceslight elements abundances

SWIMPSWIMP=(m=(mSWIMPSWIMP/m/mNLSPNLSP) ) ththNLSPNLSP

10-10 = 6.1 0.4

Fields, Sarkar, PDG (2002)


BBN constraints on EM/had injection BBN constraints on EM/had injection

EM,hadEM,had==EM,hadEM,had Br BrEM,hadEM,had YYNLSPNLSP

Decay lifetime Decay lifetime NLSPNLSP

EM/had energy releaseEM/had energy release

» » mmNLSPNLSP-m-mGG~~

Cyburt, Ellis, Fields and Olive, PRD 67, 103521 (2003)

EMEM

EM

(G

eV)

around a yeararound a year

Kawasaki, Kohri and Moroi, astro-ph/0402490

hadhad EMEM


slepton and sneutrino NLSP slepton and sneutrino NLSP

G G = (m= (mGG/m/mNLSPNLSP) ) ththNLSPNLSP~~ ~~

apply CMB and BBN constraints on (apply CMB and BBN constraints on (NLSPNLSP, , EM/hadEM/had ))

viable parameter spaceviable parameter space

NLSPNLSP, , EM,hadEM,had==EM,hadEM,had B BEM,hadEM,had Y YNLSPNLSP

J. Feng, F. Takayama, S. Suhep-ph/0404198, 0404231


superWIMP in mSUGRA superWIMP in mSUGRA

BBN EM constraints only

Stau NLSP

Ellis et. al., hep-ph/0312262

superWIMP allowed regionsuperWIMP allowed region

Usual WIMP allowed regionUsual WIMP allowed region


Collider Phenomenology Collider Phenomenology

SWIMP Dark MatterSWIMP Dark Matter

no signals in direct / indirect dark matter searchesno signals in direct / indirect dark matter searches

SUSY NLSP:SUSY NLSP: rich collider phenomenologyrich collider phenomenology

NLSPNLSP in SWIMP in SWIMP: : long lifetime long lifetime stable inside the detectorstable inside the detector

Charged slepton Charged slepton highly ionizing track, almost background freehighly ionizing track, almost background free

GMSB: gravitinoGMSB: gravitino m m »» keV keV warm not cold DMwarm not cold DM

collider searches:collider searches: other sparticle (mass)other sparticle (mass)

(GMSB) (GMSB) ¿¿ (SWIMP):(SWIMP): distinguish experimentallydistinguish experimentally

Distinguish from stau NLSP and gravitino LSP in GMSBDistinguish from stau NLSP and gravitino LSP in GMSB

Feng and Smith, in preparation.


Guaranteed signal at colliders Guaranteed signal at colliders

Birkedal, matchev, Perelstein, PRD 70, 077701 (2004).

Model independent approach: Model independent approach: DMDM < < v> v>annann productionproduction

Feng, SS, Takayama, in preparation

superWIMP:superWIMP: promising event rates at LHC/LC.promising event rates at LHC/LC.

Usual WIMP:Usual WIMP: missing energy + jet or photonmissing energy + jet or photon irreducible SM backgroundirreducible SM background

preliminarypreliminary preliminarypreliminary


Sneutrino and neutralino NLSP Sneutrino and neutralino NLSP

ssneutrino neutrino and neutralino and neutralino NLSP NLSP missing energymissing energy

ssignal: energetic jets/leptons + missing energyignal: energetic jets/leptons + missing energy

angular distribution of events angular distribution of events (LC)(LC)

Does it decay into gravitino or not?Does it decay into gravitino or not?

sneutrino case: sneutrino case: most likely gravitino is LSPmost likely gravitino is LSP

neutralino case: neutralino case: most likely neutralino LSPmost likely neutralino LSP

vs.vs.

Is Is the lightest SM superpartner sneutrino or neutralino?the lightest SM superpartner sneutrino or neutralino?

direct/indirect dark matter searchdirect/indirect dark matter search positive detection positive detection disfavor gravitino LSP disfavor gravitino LSP

precision determination of SUSY parameter: precision determination of SUSY parameter: thth,,

,, 0.23 0.23 favor gravitino LSP favor gravitino LSP


NLSPNLSP

~~GG

NLSPNLSPSMSM

~~GG

NLSPNLSPSMSM

~~GG

NLSPNLSPSMSM

~~GG

NLSPNLSPSMSM

~~GG

SMSM

Buchmuller et. al., hep-ph/0402179Hamaguchi and Ibarra, hep-ph/0412229Feng et. al., Hep-ph/0405248

Slepton trapping:Slepton trapping:Hamaguchi et. al. hep-ph/0409248Feng and Smith, hep-ph/0409278

● Decay life time Decay life time

● SM particle energy/angularSM particle energy/angular distributiondistribution……

mmGG

mmplpl

LFV LFV

… …

~ ~


Slepton trapping Slepton trapping

Slepton could live for a year, so Slepton could live for a year, so can be trapped then moved can be trapped then moved to a quiet environment to to a quiet environment to observe decaysobserve decays

Courtesy of J. Feng

LHC: 10LHC: 1066 slepton/yr possible, but slepton/yr possible, but most are fast. By optimizing trap most are fast. By optimizing trap location and shape, can catch location and shape, can catch »» 100/yr in 1000m100/yr in 1000m33 water water

LC: tune beam energy to LC: tune beam energy to produce slow sleptons, can catch produce slow sleptons, can catch 1000/yr in 1000m1000/yr in 1000m33 water water

Feng and Smith, hep-ph/0409278


ConclusionsConclusions

Gravitino could be Gravitino could be warmwarm DM: DM: m m »» keV keV

Gravitino could be Gravitino could be coldcold DM: DM: m m »» few hundred GeV few hundred GeV

thermal production: Tthermal production: TRHRH 10 101010 GeV GeV Non-thermal production: superWIMPNon-thermal production: superWIMP

SuperWIMP:SuperWIMP: gravitinogravitino LSP LSP WIMP:WIMP: sleptonslepton/sneutrino//sneutrino/neutralinoneutralino

Constraints from BBN: EM injection and Constraints from BBN: EM injection and hadronichadronic injectioninjection

viable parameter spaceviable parameter space

Rich collider phenomenologyRich collider phenomenology (no direct/indirect DM (no direct/indirect DM signal)signal) ccharged slepton:harged slepton: highly ionizing trackhighly ionizing track ssneutrinoneutrino/neutralino/neutralino:: missing energymissing energy

Slepton trappingSlepton trapping

WIMP WIMP superWIMP + SM superWIMP + SM particleparticle

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Gravitino Dark matter