LHC / ILC / Cosmology Interplay Sabine Kraml (CERN)

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LHC / ILC / Cosmology InterplaySabine Kraml
(CERN)

• WHEPP-9, Bhubaneswar, India
• 3-14 Jan 2006

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Outline

• Introduction
• Relic density of WIMPs
• SUSY case as illustrative example
• Neutralino dark matter
• Requirements for collider tests
• Implications of CP violation
• Conclusions

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What is the Universe made of?

• Cosmological data
• 4 0.4 baryonic matter
• 23 4 dark matter
• 73 4 dark energy
• Particle physics
• SM is incomplete expect new physics at TeV scale
• NP should provide the DM
• Discovery at LHC, precision measurements at ILC ?

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Dark matter candidates
Neutralino, gravitino, axion, axino, lightest KK
particle, T-odd little Higgs, branons, Q-balls,
etc., etc...
New Physics
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WIMPs (weakly interacting massive particles)

• DM must be stable, electrically neutral,
• weakly and gravitationally interacting
• WIMPs are predicted by most BSM theories
• Stable as result of discrete symmetries
• Produced as thermal relic of the Big Bang
• Testable at colliders!

Neutralino, gravitino, axion, axino, LKP, T-odd
Little Higgs, branons, Q-balls, etc., ...
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Relic density of WIMPs

• Early Universe dense and hot WIMPs in thermal
  equilibrium
• Universe expands and cools WIMP density is
  reduced through pair annihilation Boltzmann
  suppression ne-m/T
• Temperature and density too low for WIMP
  annihilation to keep up with expansion rate ?
  freeze out

Final dark matter density Wh2
1/ltsvgt Thermally avaraged cross section of all
annihilation channels
WMAP 0.094 lt Wh2 lt 0.129 _at_ 2s
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Collider tests of WIMPs

• Generic WIMP signature at LHC jets (leptons)
  ETmiss
• Great for discovery
• resolving the nature of the WIMP however not
  obvious
• Need precision measurements of masses, couplings,
  quantum numbers, .... ? ILC

LHC
WMAP
ILC
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Neutralino-LSP in the MSSM
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Minimal supersymmetric model

• SUSY Symmetry between fermions and bosons
• If R-parity is conserved the lightest SUSY
  particle (LSP) is stable ? LSP as cold dark
  matter candidate

SM particles spin Superpartners spin
quarks 1/2 squarks 0
leptons 1/2 sleptons 0
gauge bosons 1 gauginos 1/2
Higgs bosons 0 higgsinos 1/2
mix to 2 charginos 4 neutralinos
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Neutralino system
Gauginos
Higgsinos
Neutralino mass eigenstates
? LSP
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Neutralino relic density
Specific mechanisms to get relic density in
agreement with WMAP
0.094 lt Wh2 lt 0.129 puts strong bounds on the
parameter space
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mSUGRA parameter space

• GUT-scale boundary conditions m0, m1/2, A0
• plus tanb, sgn(m)
• 4 regions with right Wh2
• bulk (excl. by mh from LEP)
• co-annihilation
• Higgs funnel (tanb 50)
• focus point (higgsino scenario)

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Prediction of ltsvgt from collidersWhat do we
need to measure?

• LSP mass and decomposition
• bino, wino, higgsino admixture
• Sfermion masses (bulk, coannhilation)
• or at least lower limits on them
• Higgs masses and widths h,H,A
• tanb
• With which precision?

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What do we need to measure with which
precisionCoannihilation with staus, DMlt10 GeV

• DM(stau-LSP) to 1 GeV
• Precise sparticle mixings
• Difficult at LHC soft taus!
• Achievable at ILC
• Stau mass at threshold
• Bambade et al, hep-ph/040601
• Stau and Slepton masses
• Martyn, hep-ph/0408226
• Stau-neutralino mass difference Khotilovitch et
  al, hep-ph/0503165
• Beam polarization essential!

Allanach et al, hep-ph/0410091
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Golden decay chain at LHC

• Stau coannihilation region leptons will mostly
  be taus
• Small stau-LSP mass difference DM 10 GeV leads
  to soft ts
• Difficult to measure mtt kinematic endpoint for
  mass determination

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Determination of slepton and LSP massesat the ILC
Martyn, hep-ph/0408226
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Determination of the neutralino systemLHCILC
case study for SPS1a light -inos at ILC
neutralino4 at LHC
Desch et al., hep-ph/0312069
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What do we need to measure with which
precisionHiggsino LSP, m M1,2
Fractional accuracies needed

• Annihilation into WW and ZZ via t-channel c or
  c0
• Rate determined by higgsino fraction fHN132N142
  
• 1 precision on M1 and m
• All neutralinos/charginos mixing via pol. ee-
  Xsections
• LHC discovery via 3-body gluino decays /
  Drell-Yang

Allanach et al, hep-ph/0410091
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Scan of focus point scenario, LCC2
m0 3280 GeV, m1/2 300 GeV, A0 0, tanb 10
J.L. Feng et al., ALCPG
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What do we need to measure with which
precisionAnnihilation through Higgs
Fractional accuracies needed

• Mainly cc ? A ? bb
• CP even H exchange is
• P-wave suppressed
• mc and mA to 2-2
• (mA-2mc) and m to 5
• A width to 10
• g(Acc)N132-N142, g(Abb)hb, ....

Allanach et al, hep-ph/0410091
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Influence of mA on evaluation of Wh2
? large uncertainty if lower limit on mA is not
gtgt 2 mLSP Birkedal et al, hep-ph/0507214
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e e_ ? H A

• A not produced in Higgs-Strahlung, need ee_ ? HA
• H,A masses to 1 GeV limitation by kinematics!
• Widths only to 20-30
• Production in gg mode can help a lot

Heinemeyer et al., hep-ph/0511332
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Heavy Higgses at LHC
H/A in cascade decays
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• For a precise prediction of Wh2
• compatible with WMAP acurracy
• we need precision measurements
• of most of the SUSY spectrum
• ? LHC/ILC synergy

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So far considered CP conserving MSSM What if CP
is violated? we actually need new sources of CP
violation beyond the SM for baryogenesis
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CP violation

• In the general MSSM, gaugino and higgsino mass
  parameters and trilinear couplings can be
  complex
• Important influence on sparticle production and
  decay rates ? Expect similar influence on ltsvgt

NB1 M2 can also be complex, but its phase can be
rotated away. NB2 CPV phases are strongly
constrained by dipole moments we set fm0
and assume very heavy 1st2nd generation
sfermions
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CP violation Higgs sector

• Non-zero phases induce CP violation in the Higgs
  sector through loops ? mixing of h,H,A
• Couplings to neutralinos

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Previous studies of neutralino relic density
with CP violation
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CPV analysis with micrOMEGAs

• M1 150, M2 300, At 1200 GeV, tanb 5
• masses of 3rd gen 500 GeV, 1st2nd gen 10 TeV
• bino-like LSP, m 150 GeV
• Wh2 lt 0.129 needs annihilation through Higgs
• Scenario 1 m 500 GeV ? small mixing in Higgs
  sector
• Scenario 2 m 1 TeV ? large mixing in Higgs
  sector

Higgs mixing Im(Atm)
Belanger, Boudjema, SK, Pukhov, Semenov, in
LesHouches05
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CPV with micrOMEGAs
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Scenario 2
Key parameter is distance from pole
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Recall Higgs funnels in mSUGRA
mA
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Higgs funnel with large Higgs CP-mixing
h2
h3
h3
h3
Green bands 0.094 lt Wh2 lt 0.129 dmi mhi -
2mLSP, i2,3
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Higgs funnel with large Higgs CP-mixing
h2
h3
h3
h3
Green bands 0.094 lt Wh2 lt 0.129
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Higgs funnel with large Higgs CP-mixing
h3
Green bands 0.094 lt Wh2 lt 0.129 dmi mhi -
2mLSP, i2,3
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• CP violation
• is a very interesting option
• can have order-of-magnitude effect on Wh2
• needs to be tested precisely
• However computation of annihilation cross
  sections at only at tree level radiative
  corrections may be sizeable!

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Assume we have found SUSY with a neutralino LSP
and made very precise measurements of all
relevant parameters What if the inferred Wh2
is too high?
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Solution 1Dark matter is superWIMP
e.g. gravitino or axino
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Solution 2R-parity is violated after all

• RPV on long time scales
• Late decays of neutralino LSP reduce the number
  density actual CDM is something else
• Very hard to test at colliders
• Astrophysics constraints?

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Solution 3Cosmological assumptions are wrong

• Our picture of dark matter as a thermal relic
• from the big bang may be to simple
• The early Universe may have evolved differently
• ....
• ....
• ....

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Conclusions

• We expect new physics beyond the SM
• to show up at the TeV energy scale
• to provide the dark matter of the Universe
• Using the example of neutralino dark matter
  I have shown that precison measurements at both
  LHCILC are necessary to pin down the nature and
  properties of the dark matter
• Wh2 1/ltsvgt from LHC/ILC ? WMAP acurracy
• Direct detection in addition to pin down DM

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LHC
WMAP
ILC
Accuracies of determining the LSP mass and its
relic density Alexander et al., hep-ph/0507214
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What if only part of the spectrum is accessible?

• Part of the spectrum may escape detection
• Too heavy sparticles, only limits on masses
• Not enough sensitivity, e.g. H,A
• Only LHC data available, ....
• Model assumptions, fits of specific models, etc,
• to obtain testable predicions or to test
  models
• Famous example Fit of mSUGRA to LHC data at
  SPS1a
• Need precise predictions within models of SUSY
  breaking

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Comparison of SUSY spectrum codes

• Computation of SUSY spectrum with 4
  state-of-the-art SUSY codes Isjet, Softsusy,
  Spheno, Suspect
• 2loop RGEs 1loop threshold corrections,
• 1loop corr. to Yukawa couplings, ...
• Computation of relic desity with micrOMEGAs
• Mapped mSUGRA parameter space for
• differences in predictions of Wh2
• differences in WMAP exclusions
• due to spectrum uncertainties

Belanger, SK, Pukhov, hep-ph/0502079
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Uncertainties from sparticle mass predictions
O(1) moderate parameters, stau coannihilation
Stau-LSP mass difference! d(DM) 1 GeV ? dW 10
Contours of Wh20.129
Belanger, SK, Pukhov, hep-ph/0502079
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Uncertainties from sparticle mass predictions
large tanb and the Higgs funnel
Belanger, SK, Pukhov, hep-ph/0502079
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• There is need to improve computations and tools
  in order to match acurracies required by
  WMAP/Planck
• Improvements in spectrum computations are
  discussed in Baer, Ferrandis, SK, Porod,
  hep-ph/0511123