Transcript ASBS2 - University of Arizona

Dark Matters
Shufang Su • U. of Arizona
We are living through a revolution in our
understanding of the Universe
on the largest scales
For the first time in history,
we have a complete picture of the Universe
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DM evidence: rotation curves
Rotation curves of galaxies and galactic clusters
Vc » const
NGC 2403
Constrain m
Dark matter
in halo
Vc » 1/r
i=i/c
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Dark matter evidence: supernovae
Supernovae
then
now
Constrain m-
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Dark matter evidence: CMB
Cosmic Microwave Background
Constrain +m
then
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now
5
Synthesis
 » 0.5%
 » 0.5%
=3%
=23% § 4%
=73% § 4%
 Remarkable agreement
 Remarkable precision (~10%)
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Dark matter vs. dark energy
We know how much, but no idea what it is.
Dark matter
Dark energy
No known particles contribute
All known particles contribute
Probably tied to mweak » 100 GeV
Probably tied to mPlanck » 1019 GeV
Several compelling solutions
No compelling solutions
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Standard Model
Quarks
u
d
c
s
t
b
Leptons
e
e




Gauge boson
(force carrier)

W§,Z
g
Higgs
H
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CDM requirements
 Stable
 Non-baryonic
 Neutral
 Cold (massive)
 Correct density
 Gravitational
interacting
Not
for cosmology
observations
SM is a very
successful
theoretical
framework
No
good
candidates
for CDMtoindate
SM
−all
Dark
Matter
describes
experimental
observations
− Cosmology constant
Dark Matters − Baryon asymmetry …
9
New physics beyond SM
DM problem provide precise, unambiguous evidence for new physics
Independent motivation for new physics in particle physics
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New physics beyond SM
 SM is an effective theory below some energy scale  » TeV
Hierarchy problem
Naturalness problem
(mH2)physical
mplank 1019 GeV
H
mEW 102 GeV
¼ (mH2)0
+ 2
 (100 GeV)2
-(1019 GeV)2
(1019 GeV)2
precise cancellation
up to 1034 order
 New physics to protect electroweak scale
 new symmetry: supersymmetry
 new space dimension: extra-dimension
 …
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Dark matter in new physics
Dark Matter: new stable particle
in many theories, dark matter is easier to explain than no dark matter
 there are usually many new weak scale particle
 constraints (proton decay, large EW corrections)
discrete symmetry
stability
good dark matter candidate
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Dark matter candidates
Many ideas of DM candidates:
 superWIMPs
 WIMP
 primodial black holes
 self-interacting particles
 axions
 self-annihilating particles
 warm gravitinos
 fuzzy dark matter
motivated independently
 Qappear
balls in particle physics models
 branons
by attempts to solve Electroweak
 wimpzillas
 … Symmetry Breaking
 relic density are determined by mpl and mweak
mass and interaction strengths span many, many orders of magnitude
 naturally around the observed value
 no need to introduce and adjust new energy scale
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WIMP dark matter
Thermal
WIMP:
Weakequilibrium
Interacting Massive Particle
 $ ff
WIMP
Universe cools:
N=NEQ=e-m/T
WIMP » 1
h i
Freeze out, N » const an
 mWIMP» mweak
 an » weak2 mweak-2
naturally around
the observed value
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Dark matter detection
DM
DM
DM
f
Cross symmetry
f
DM
DM annihilation
f
f
 / 1/h  i
Not overclose universe

Efficient annihilation then
DM scattering
Efficient scattering now
direct DM direction
Efficient annihilation now
indirect DM direction
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Direct detection
DM
DAMA Signal and
Others’ Exclusion Contours
CDMS
Measure nuclear recoil energy
detector
DAMA
CDMS
EDELWEISS
WIMP
CDMS II
CDMS (2004)
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Direct detection: future
Near Future
Future
Theoretical Predictions
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Baer, Balazs, Belyaev, O’Farrill (2003)
Current Sensitivity
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Indirect detection
DM
DM
Dark Matter annihilates
detector
recipe
in
to
a place
,
some particles
.
which are detected by
an experiment
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Dark Matter annihilates
recipe
in center of the sun to
a place
neutrinos
,
some particles
which are detected by AMANDA, ICECUBE.
an experiment
earth

Dark matter density in
the sun, capture rate
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Dark Matter annihilates
in galactic center to
recipe
a place
photons
,
some particles
which are detected by GLAST, HESS.
an experiment
HESS
Dark matter density in
the center of the galaxy
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Dark Matter annihilates
in
the halo
recipe
a place
to
positions
,
some particles
which are detected by AMS on the ISS.
an experiment
Dark matter density
profile in the halo
AMS
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Minimal Supersymmetric Standard Model (MSSM)
SM particle
Squarks
Spin differ by 1/2
»
u
»
»
c
d
»
s
t
»
b
sleptons
»
e
»
e
»


»

»


»

Gauginos
»0
»
Higgsino
»
B
»
,
CDM requirements
»
»
W§,W0
(Hu+,Hu0)
superpartner
»
(Hd0,
»
g
»
Hd-)
Stable
Non-baryonic
Neutral
Cold
m > 45 GeV
 Correct density
weak interaction
 gravitational
interacting




Supersymmetry breaking, m » TeV
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Neutralino LSP as DM
 new weak scale particle

constraints
discrete symmetry
stability
dark matter candidate
super-partners
proton decay
R-parity: SM particle + super-partner lightest supersymmetric particle (LSP) stable
LSP  SM particle, LSP  super particle
~0
B ,
~
W0 ,
Superpartner of
gauge bosons
~
Hd0,

~
Hu0
Superpartner of
Higgs bosons
neutralinos i0, i=1…4 mass eigenstates
Neutralino LSP: 10 as Dark Matter
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Neutralino relic density
0.1  h2  0.3 (pre-WMAP)
CMSSM
 Cosmology excludes much of
the parameter space
 too big
 cosmology focuses attention
on particular regions
 just right
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Collider study of dark matter
Can study those regions at colliders
Tevatron
LHC
-p
p
Now
p
p
ILC
2007
Precise determination of new particle mass and coupling

Determine DM mass, relic density
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Relic density determination
Feng et. al. ILC cosmology working group
ILC
LHC (“best case scenario”)
WMAP
(current)
Planck
(~2010)
LCC1
Parts per mille agreement for   discovery of dark matter
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Comparison of pre-LHC SUSY searches
LHC seeach
DM search
Pre-WMAP
Post-WMAP
 DM searches are complementary to collider searches
 When combined, entire cosmologically attractive region will
be explored before LHC ( » 2007 )
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Synergy
Collider Inputs
Weak-scale Parameters
DM Annihilation
Relic Density
DM-N Interaction
Indirect Detection
Direct Detection
Astrophysical and Cosmological Inputs
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Alternative dark matter
All of the signals rely on DM having EW interactions.
Is this required?
NO!
CDM requirements
 Stable
 Non-baryonic
 Neutral
 Cold (massive)
  Correct density
  Gravitational
interacting
(much weaker
than electroweak)
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But the relic density argument
strongly prefers weak interactions.
DM  -1
 (gravitational coupling)-2
●  too small
● DM too big
overclose the Universe
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superWIMP
WIMP  superWIMP + SM particles
Feng, Rajaraman and Takayama (2003)
104 s  t  108 s
SWIMP
SM
WIMP
superWIMP
e.g. Gravitino LSP
LKK graviton
WIMP
106
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 neutral
 charged
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superWIMP : an example
SUSY case
WIMP  superWIMP + SM particles
Charged slepton
Superpartner of lepton
Gravitino
Superpartner of graviton
superWIMP
1
»
mpl2
WIMP
SM particle
Decay lifetime  planck mass
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change light element
abundance predicted
by BBN
Strong constraints !
32
BBN constraints
?
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Fields, Sarkar, PDG (2002)
/10-10 = 6.1 0.4
Feng, Rajaraman, Takayama (2003)
Big bang nucleosynthesis
Cosmological signals: BBN, CMB
33
superWIMP in mSUGRA
Ellis et. al., hep-ph/0312262
BBN EM constraints only
Usual WIMP allowed region
superWIMP allowed region
Stau NLSP
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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
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 neutral WIMP
missing energy
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● Decay life time
● SM particle energy/angular
distribution …
 mG~
 mpl …
 Probes gravity in a particle
physics experiments!
SM
NLSP
SM
NLSP
~
G
SM
NLSP
 BBN, CMB in the lab
~
G
~
G
SM
NLSP
~
G
SM
NLSP
 Precise test of supergravity:
gravitino is a graviton partner
~
G
How to trap slepton?
Hamaguchi et. al. hep-ph/0409248
Feng and Smith, hep-ph/0409278
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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
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Conclusion
We now know the composition of the Universe
No known particle in the SM can be DM
 precise, unambiguous evidence for new
physics
New physics
 new stable particle as DM candidate
WIMP: neutralino LSP in MSSM
direct/indirect DM searches, collider studies
synergy between cosmology and particle physics
superWIMP
slepton trapping
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