lhc / ilc / cosmology interplay sabine kraml (cern) whepp-9, bhubaneswar, india 3-14 jan 2006
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LHC / ILC / Cosmology Interplay
Sabine Kraml (CERN)
WHEPP-9, Bhubaneswar, India
3-14 Jan 2006
WHEPP-9 Bhubaneswar 2S. Kraml
Outline
Introduction Relic density of WIMPs SUSY case as illustrative example
Neutralino dark matter Requirements for collider tests Implications of CP violation
Conclusions
WHEPP-9 Bhubaneswar 3S. Kraml
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 ?
WHEPP-9 Bhubaneswar 4S. Kraml
Dark matter candidates
Neutralino, gravitino, axion, axino, lightest KK particle, T-odd little Higgs, branons, Q-balls, etc., etc...
New Physics
WHEPP-9 Bhubaneswar 5S. Kraml
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., ...
WHEPP-9 Bhubaneswar 6S. Kraml
Relic density of WIMPs(1) Early Universe dense and hot;
WIMPs in thermal equilibrium
(2) Universe expands and cools; WIMP density is reduced through pair annihilation; Boltzmann suppression: n~e-m/T
(3) Temperature and density too low for WIMP annihilation to keep up with expansion rate → freeze out
Final dark matter density: h2 ~ 1/<v>Thermally avaraged cross section of all annihilation channels
WMAP: 0.094 < h2 < 0.129 @ 2
WHEPP-9 Bhubaneswar 7S. Kraml
Collider tests of WIMPs
Generic WIMP signature at LHC: jets (+leptons) + ET
miss
Great for discovery; resolving the nature of the WIMP however not obvious
Need precision measurements of masses, couplings, quantum numbers, .... → ILC
WMAP
LHC
ILC
WHEPP-9 Bhubaneswar 8S. Kraml
Neutralino-LSP in the MSSM
WHEPP-9 Bhubaneswar 9S. Kraml
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
WHEPP-9 Bhubaneswar 10S. Kraml
Neutralino system
Neutralino mass eigenstates
Gauginos
Higgsinos
→ LSP
WHEPP-9 Bhubaneswar 11S. Kraml
Neutralino relic densitySpecific mechanisms to get relic density in agreement with WMAP
0.094 < h2 < 0.129 puts strong bounds on the parameter space
WHEPP-9 Bhubaneswar 12S. Kraml
mSUGRA parameter space
GUT-scale boundary conditions: m0, m1/2, A0
[plus tan, sgn()]
4 regions with right h2 bulk (excl. by mh from LEP)
co-annihilation Higgs funnel (tan ~ 50) focus point (higgsino scenario)
WHEPP-9 Bhubaneswar 13S. Kraml
Prediction of <v> from colliders:What do we need to measure?
LSP mass and decompositionbino, wino, higgsino admixture
Sfermion masses (bulk, coannhilation)or at least lower limits on them
Higgs masses and widths: h,H,A tan
With which precision?
WHEPP-9 Bhubaneswar 14S. Kraml
What do we need to measure with which precision:
Coannihilation with staus, M<10 GeV
M(stau-LSP) to 1 GeV Precise sparticle mixings Difficult at LHC; soft tau´s! Achievable at ILC:
Stau mass at thresholdBambade et al, hep-ph/040601
Stau and Slepton massesMartyn, hep-ph/0408226
Stau-neutralino mass difference Khotilovitch et al,
hep-ph/0503165
Beam polarization essential! [Allanach et al, hep-ph/0410091]
~
WHEPP-9 Bhubaneswar 15S. Kraml
Golden decay chain at LHC
Stau coannihilation region: leptons will mostly be taus
Small stau-LSP mass difference M ≤ 10 GeV leads to soft ´s
Difficult to measure mkinematic endpoint for mass determination
WHEPP-9 Bhubaneswar 16S. Kraml
Determination of slepton and LSP massesat the ILC
[Martyn, hep-ph/0408226]
WHEPP-9 Bhubaneswar 17S. Kraml
Determination of the neutralino systemLHC+ILC case study for SPS1a: light -inos at ILC; neutralino4 at LHC
[Desch et al., hep-ph/0312069]
WHEPP-9 Bhubaneswar 18S. Kraml
What do we need to measure with which precision:
Higgsino LSP, ~ M1,2
Annihilation into WW and ZZ via t-channel ± or
Rate determined by higgsino fraction fH=N13
2+N142
1% precision on M1 and
All neutralinos/charginos; mixing via pol. e+e- Xsections
LHC: discovery via 3-body gluino decays / Drell-Yang
[Allanach et al, hep-ph/0410091]
Fractional accuracies needed
WHEPP-9 Bhubaneswar 19S. Kraml
[J.L. Feng et al., ALCPG]
Scan of focus point scenario, LCC2m0 = 3280 GeV, m1/2 = 300 GeV, A0 = 0, tanb = 10
WHEPP-9 Bhubaneswar 20S. Kraml
What do we need to measure with which precision:
Annihilation through Higgs
Mainly → A → bb CP even H exchange is
P-wave suppressed mandmAto 2%-2‰
(mA-2m) and to 5% A width to 10%
g(A)~N132-N14
2, g(Abb)~hb, ....
Fractional accuracies needed
[Allanach et al, hep-ph/0410091]
WHEPP-9 Bhubaneswar 21S. Kraml
Influence of mA on evaluation of h2
→ large uncertainty if lower limit on mA is not >> 2 mLSP
[Birkedal et al, hep-ph/0507214]
WHEPP-9 Bhubaneswar 22S. Kraml
e+ e_
→ H A
[Heinemeyer et al., hep-ph/0511332]
A not produced in Higgs-Strahlung, need e+e_ → HA
H,A masses to ~1 GeV; limitation by kinematics! Widths only to 20%-30% Production in mode can help a lot
WHEPP-9 Bhubaneswar 23S. Kraml
Heavy Higgses at LHCH/A in cascade decays
WHEPP-9 Bhubaneswar 24S. Kraml
For a precise prediction of h2
compatible with WMAP acurracy we need precision measurements
of most of the SUSY spectrum
→ LHC/ILC synergy
WHEPP-9 Bhubaneswar 25S. Kraml
So far considered CP conserving MSSM
What if CP is violated?[we actually need new sources of CP violation
beyond the SM for baryogenesis]
WHEPP-9 Bhubaneswar 26S. Kraml
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 <v>
NB1: M2 can also be complex, but its phase can be rotated away.
NB2: CPV phases are strongly constrained by dipole moments;
we set =0 and assume very heavy 1st+2nd generation sfermions
WHEPP-9 Bhubaneswar 27S. Kraml
CP violation: Higgs sector Non-zero phases induce CP violation in the Higgs sector
through loops → mixing of h,H,A:
Couplings to neutralinos:
WHEPP-9 Bhubaneswar 28S. Kraml
Previous studies of neutralino relic density with CP violation
WHEPP-9 Bhubaneswar 29S. Kraml
CPV analysis with micrOMEGAsM1 = 150, M2 = 300, At = 1200 GeV, tan = 5
masses of 3rd gen: 500 GeV, 1st+2nd gen: 10 TeV
bino-like LSP, m ~ 150 GeV h2 < 0.129 needs annihilation through Higgs
Scenario 1: = 500 GeV → small mixing in Higgs sector Scenario 2: = 1 TeV → large mixing in Higgs sector
Higgs mixing ~ Im(At)
[Belanger, Boudjema, SK, Pukhov, Semenov, in: LesHouches‘05]
WHEPP-9 Bhubaneswar 30S. Kraml
CPV with micrOMEGAs
WHEPP-9 Bhubaneswar 31S. Kraml
Scenario 2
Key parameter is distance from pole
WHEPP-9 Bhubaneswar 32S. Kraml
Recall Higgs funnels in mSUGRA
mA=
WHEPP-9 Bhubaneswar 33S. Kraml
Higgs funnel with large Higgs CP-mixing
Green bands: 0.094 < h2 < 0.129
dmi = mhi - 2mLSP, i=2,3
h3 h3
h3
h2
WHEPP-9 Bhubaneswar 34S. Kraml
Higgs funnel with large Higgs CP-mixing
Green bands: 0.094 < h2 < 0.129
h3 h3
h3
h2
WHEPP-9 Bhubaneswar 35S. Kraml
Higgs funnel with large Higgs CP-mixing
Green bands: 0.094 < h2 < 0.129
dmi = mhi - 2mLSP, i=2,3
h3
WHEPP-9 Bhubaneswar 36S. Kraml
CP violation is a very interesting option can have order-of-magnitude effect on h2
needs to be tested precisely
However: computation of annihilation cross sections at only at tree level; radiative corrections may be sizeable!
WHEPP-9 Bhubaneswar 37S. Kraml
Assume we have found SUSY with
a neutralino LSP and made very precise
measurements of all relevant parameters:
What if the inferred
h2 is too high?
WHEPP-9 Bhubaneswar 38S. Kraml
Solution 1:
Dark matter is superWIMP
e.g. gravitino or axino
WHEPP-9 Bhubaneswar 39S. Kraml
Solution 2:
R-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?
WHEPP-9 Bhubaneswar 40S. Kraml
Our picture of dark matter as a thermal relic
from the big bang may be to simple The early Universe may have evolved differently .... .... ....
Solution 3:
Cosmological assumptions are wrong
WHEPP-9 Bhubaneswar 41S. Kraml
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 LHC+ILC are necessary to pin down the nature and properties of the dark matter
h2 ~ 1/<v> from LHC/ILC ↔ WMAP acurracy Direct detection in addition to pin down DM
WHEPP-9 Bhubaneswar 42S. Kraml
WMAP
LHC
ILC
Accuracies of determining the LSP mass and its relic density[Alexander et al., hep-ph/0507214]
WHEPP-9 Bhubaneswar 43S. Kraml
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
WHEPP-9 Bhubaneswar 44S. Kraml
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 h2
differences in WMAP exclusions
due to spectrum uncertainties
[Belanger, SK, Pukhov, hep-ph/0502079]
WHEPP-9 Bhubaneswar 45S. Kraml
[Belanger, SK, Pukhov, hep-ph/0502079]
Stau-LSP mass difference!M) ~ 1 GeV → ~ 10%
Uncertainties from sparticle mass predictions O(1%)moderate parameters, stau coannihilation
Contours of h2=0.129
WHEPP-9 Bhubaneswar 46S. Kraml
[Belanger, SK, Pukhov, hep-ph/0502079]
Uncertainties from sparticle mass predictions: large tan and the Higgs funnel
WHEPP-9 Bhubaneswar 47S. Kraml
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]