Cosmology and the ILC

G. Bélanger

LAPTH- Annecy

PLAN Cosmology <-> colliders

• Dark matter • Baryon asymmetry• Dark energy?

Neutralino dark matter• Precision studies• Correlation with direct/indirect detection

Dark matter : beyond MSSM Electroweak Baryogenesis Conclusions

What is the universe made of?

Although evidence for dark matter has been around for a while both at scale of galaxy clusters (Zwicky 1933) and of galaxies (rotation curves), in 2003 with CMB anisotropy map achieve precise determination of cosmological parameters

What is the universe made of? In recent years : new

precise determination of cosmological parameters

Data from CMB (WMAP) agree with the one from clusters and supernovae • Dark matter: 23+/- 4%• Baryons: 4+/-.4%• Dark energy 73+/-4%• Neutrinos < 1%

Search for dark matter In 2003 WMAP has measured

relic density +/-15% (2σ)• This year new results

In 2007 PLANCK will start operating, goal is to reach +/- 5-6% on relic density(2σ)

In 2008 LHC will start, might have discovery and measurements of supersymmetric particles (or other NP) within a few years

In the meantime direct detection and indirect detection experiments continue to run with improved detectors

HEPAP subpanel report onfuture particle colliders

What is dark matter/dark energy Dark matter

• Related to physics at weak scale

• New physics at weak scale can also solve EWSB

• Many possible solutions: new particle that exist in some NP models, not necessarily designed for DM

Dark energy• Related to Planck scale physics

• NP for dark energy might affect cosmology and dark matter

• Neutrinos (they exist but only small component of DM)

• Supersymmetry with R parity conservation

• Neutralino LSP

• Gravitino

• Axino

• Kaluza-Klein dark matter• UED (LKP )

• LZP is neutrino-R (in Warped Xdim models with matter in the bulk)

• Branons

• Little Higgs with T-parity• ……

Relic density of wimps

In early universe WIMPs are present in large number and they are in thermal equilibrium

As the universe expanded and cooled their density is reduced through pair annihilation

Eventually density is too low for annihilation process to keep up with expansion rate

• Freeze-out temperature LSP decouples from standard

model particles, density depends only on expansion rate of the universe

Freeze-out

Relic density

A relic density in agreement with present measurements Ωh2 ~0.1 requires typical weak interactions cross-section

Accuracy on relic density of LSP Goal is to reach at least the same precision on the

prediction of the relic density as the experimental one

• +X

Right now depending on particle physics models (even if only consider supersymmetry) predictions vary by orders of magnitude

For different cosmological model also vary by orders of magnitude• Changes in H affect the freeze-out temperature• New terms in Boltzmann equations

Dark matter : cosmo/astro/pp Wimps have roughly right value for relic density Neutralinos are wimps but not all SUSY models are acceptable Precise measurement of relic density constrain models

• Generic class of SUSY models that are OK Direct/Indirect detection : search for dark matter establish

that new particle is dark matter constrain models Colliders : which model for NP/ prediction for σv/confront

cosmology• LHC: discovery of new physics, dark matter candidate and/or

new particles• ILC: extend discovery potential of LHC + precision

measurements

How well this can be done strongly depends on model for NP

Neutralino LSP Prediction for relic density depend on parameters of

model• Mass of neutralino LSP

• Nature of neutralino : determine the coupling to Z, h, A …• M1 <M2< bino <M1,M2 Higgsino

• M2<M1< Wino

Neutralino annihilation

3 typical mechanisms for χ annihilation• Bino annihilation into ff

• σ ~ mχ2/mf

4

• Mixed bino-Higgsino (wino)

• Coupling depends on Z12,Z13,Z14, mixing of LSP

• Annihilation near resonance (Higgs)

Neutralino annihilation

3 typical mechanisms for χ annihilation• Bino annihilation into ff

• σ ~ mχ2/mf

4

• Mixed bino-Higgsino (wino)• Coupling depends on

Z12,Z13,Z14

• Annihilation near resonance (Higgs)• Need some coupling to A,

some mixing with Higgsino

Coannihilation

If M(NLSP)~M(LSP) then maintains thermal equilibrium between NLSP-LSP even after SUSY particles decouple from standard ones

Relic density depends on rate for all processes involving LSP/NLSP SM

All particles eventually decay into LSP, calculation of relic density requires summing over all possible processes

Important processes are those involving particles close in mass to LSP Public codes to calculate relic density: micrOMEGAs, DarkSUSY, IsaRED

Exp(- ΔM)/T

Neutralino co-annihilation

Can occur with all sfermions, gauginos• Bino LSP (sfermion

coannihilation)

• Higgsino LSP- coannihilation with chargino and neutralinos

What happens in generic SUSY models, does one gets the right value for the relic density?

• mSUGRA (only 5 parameters)

• M0, M1/2, tan β, A0,

• Other models MSSM (at least 19 parameters)

The mSUGRA case Theoretical assumption: the model

is known mSUGRA (CMSSM) Useful case study contains (almost)

all typical processes for neutralino (co)-annihilation

bino – LSP :annihilation in fermion pairs• In most of mSUGRA parameter space• Works well for light sparticles but hard to

reconcile with LEP/Higgs limit (small window open)

Sfermion coannihilation• Staus or stops• More efficient, can go to higher masses

Mixed bino-Higgsino: annihilation into W/Z/t pairs

Resonance (Z, light/heavy Higgs)

Mt=175GeV

Mt=178Mt=178

The mSUGRA case -WMAP

Bino – LSP Sfermion Coannihilation Mixed Bino-Higgsino

• Annihilation into W pairs

• In mSUGRA unstable region, mt dependence, works better at large tanβ

Resonance (Z, light/heavy Higgs)• LEP constraints for light Higgs/Z

• Heavy Higgs at large tanβ (enhanced Hbb vertex)

WMAP and SUSY dark matter

The mSUGRA model seems fine-tuned (either small ΔM or Higgs resonance) . • The LSP is bino

Not generic of other SUSY models, a good dark matter candidate is a mixed bino/Higgsino ….• In particular, main annihilation into gauge boson pairs works well

for Higgsino fraction ~25%

The mixed bino/Higgsino can be found in many models: mSUGRA (focus), non-universal SUGRA, string inspired (moduli-dominated) models, split SUSY, NMSSM….

Which scenario? Potential for SUSY discovery at LHC/ILC

Some of these scenarios will be probed at LHC/ILC and/or direct /indirect detection experiments

Corroborating two signals SUSY dark matter

LHC• Squarks, gluinos < 2- 2.5 TeV• Sparticles in decay chains• mSUGRA: probe significant parameter

space, heavy Higgs difficult, large m0-m1/2 also.

• Other models : similar reach in masses

ILC• Production of any new sparticles within

energy range• Extend the reach of LHC in particular in

“focus point” of mSUGRA Baer et al., hep-ph/0405210

Probing cosmology using collider information

Within the context of a given model can one make precise predictions for the relic density at the level of WMAP(10-15%) and even PLANCK (3-6%) (2007) therefore test the underlying cosmological model.

• Assume discovery SUSY, precision from LHC?

• Precision from ILC?

Answer depends strongly on underlying NP scenario, many parameters enter computation of relic density, only a handful of relevant ones for each scenario – work is going on in North America, Asia and Europe both for LHC and ILC, within mSUGRA or MSSM• Moroi, Bambade, Richard, Zhang, Martyn, Tovey, Polesello, Lari, D. Zerwas,

Allanach, Belanger, Boudjema, Pukhov, Battaglia, Birkedal, Gray, Matchev, Alexander, Fields, Hertz, Jones, Meyraiban, Pivarski, Peskin, Dutta, Kamon, Arnowitt, Khotilovith, Nojiri…

Precision on relic density

Concentrate on MSSM, although choice of case study done within mSUGRA

Examples of typical scenarios• SPA1A (bulk+coannihilation)

• Coannihilation

• LCC2 (Higgsino or focus)

• Heavy Higgs

One example: SPA1A

‘Bulk’+ stau coannihilation• Annihilation into fermions

• Coannihilation with staus

Relevant parameters : LSP mass, couplings, slepton masses• stau-neutralino mass

difference (for coannihilation processes)

M0=70, M1/2=250, A0=-300,tanβ=10

Determination of parameters LHC : SPA1A

Decay chain

Signal: jet +dilepton pair Can reconstruct four

masses from endpoint of ll and qll• In particular stau-neutralino

mass difference Here Δm (NLSP-LSP) =

2.5GeV

Mixing in the stau sector obtained from

For LSP couplings need 3 masses (χ1 χ2 χ4) and assume tanβ

Assume tanβ known + limit on heavy stau and on heavy Higgs

LHC: SPA1A

LHC: roughly the WMAP precision can be achieved within MSSM if good precision on position of ττ edge

Also important to measure sfermion/neutralino parameters and setting limits on Higgs, other coannihilation particles…

Nojiri et al, hep-ph/0512204

LHC: SPA1A

LHC: roughly the WMAP precision can be achieved within MSSM if good precision on position of ττ edge

Also important to measure sfermion/neutralino parameters and setting limits on Higgs, other coannihilation particles…

Nojiri et al, hep-ph/0512204

Even in this favourable scenario, LHC can reach only roughly WMAP precision if no underlying assumption about mSUGRA

Other mSUGRA and even more so other MSSM scenarios will be hard for LHC

Need ILC precision• Is that enough?

MSSM: stau coannihilation Challenge: measuring precisely

mass difference Why? Ωh2 dominated by Boltzmann

factor exp(- ΔM/T) Stau-neutralino mass

difference need to be measured to ~1 GeV

ILC: can match the precision of WMAP and even better• 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

Allanach et al, JHEP2005

Precision required for ΔΩ/Ω~10%

Higgsino in MSSM: mSUGRA-inspired focus point

No dependence on mt except near threshold

Relic density depend on 4 neutralino parameters, M1, M2, , tanβ

To achieve WMAP precision on relic density must determine

• (M1,) 1% .

• tanβ~10%

• Is it possible?

…. Higgsino LSP If squarks are heavy difficult

scenario for LHC • only gluino accessible,

chargino/neutralino in decays

• mass differences could be measured from neutralino leptonic decays,

• How well can gaugino parameters can be reconstructed?

Light Higgsinos possibly many accessible states at ILC

•Baltz, et al , hep-ph/0602187

… Higgsino LSP Recent study of determination

of parameters and reconstruction of relic density in this scenario (LCC2)

LHC: not enough precision

ILC: chargino pair production sensitive to bino/Higgsino mixing parameter

ILC: roughly 10% precision on Ωh2

Baltz et al hep-ph/0602187

Annihilation through Higgs

In mSUGRA relevant at large tanβ

Important parameters : mass LSP, mA, Γ(A)

Right at the peak, annihilation much too effective

Allanach et al, JHEP2005

Higgs funnel (LCC4)

Some information on MA is not sufficient to have precise prediction of relic density, must measure also width

In this scenario (MA~410GeV), width can only be measured at ILC-1000 ( ~10%)

Leads to ΔΩ/Ω~ 18%

M0=380 M1/2=420 tanβ=53

Summary - Relic density

Complementarity astroparticle/ colliders

Indirect/direct detection can find (some hints from Egret, Hess..) signal for dark matter

Many experiments under way, more are planned • Direct: CDMS, Edelweiss, Dama, Cresst, Zeplin Xenon, Genius… • Indirect: Hess, Veritas, Glast, HEAT, Pamela, AMS, Amanda, Icecube, Antares …

Can check if compatible with some SUSY or other scenario Complementarity with LHC/ILC:

• Establishing that there is dark matter• Probing SUSY dark matter candidates

Models that give good signal in direct/indirect detection (mixed bino/Higgsino LSP) also give signal at ILC

Direct detection: scattering of LSP on nuclei through Higgs/squark exchange Indirect detection of product of dark matter pair annihilation in space

(positrons, photons, neutrinos) • Best signal for hard positrons or hard photons from neutralino annihilation into WW,ZZ

Clear complementarity between (in)direct detection – LHC -ILC

LHC+ILC + indirect detection

With measurements from LHC+ILC can we refine predictions for direct/indirect detection?

Consider our Higgsino example (LCC2)

Prediction for annihilation cross-section at v=0

E. Baltz et al hep-ph/0602187

Other dark matter candidates

Gravitinos (axinos…) Universal extra-dimensions : LKP Warped extra-dimensions: LZP Little Higgs models: LTP …

Other DM candidates: KK UED

• Minimal UED: LKP is B (1), partner of hypercharge gauge boson

• s-channel annihilation of LKP (gauge boson) typically more efficient than that of neutralino LSP

• Compatibility with WMAP means rather heavy LKP, 500-600 GeV (Tait, Servant)

• New calculation show that all coannihilation should be included as well as radiative corrections to masses (Kong, Matchev)

• Within LHC range, relevant for > TeV linear collider

Other DM candidates: KK

Warped Xtra-Dim (Randall-Sundrum)• GUT model with matter in the bulk

• Solving baryon number violation in GUT models stable Kaluza-Klein particle

• Example based on SO(10) with Z3 symmetry: LZP is KK right-handed neutrino• Agashe, Servant, hep-ph/0403143

Dark matter in Warped X-tra Dim Compatibility with WMAP for

LZP range 50- >1TeV LZP is Dirac particle,

coupling to Z through Z-Z’ mixing and mixing with LH neutrino

Large cross-sections for direct detection• Signal for next generation of

detectors in large area of parameter space

What can be done at colliders : identify model, determination of parameters and confronting cosmology? Agashe, Servant, hep-ph/0403143

Other DM candidates: LTP

Little Higgs models with global symmetry broken at TeV scale• light Higgs is a pseudo Nambu-Goldstone boson,

Littlest Higgs model: simplest model but need a discrete symmetry (T-parity) to be consistent with electroweak precision measurements

Heavy photon (partner of hypercharge boson) is LTP Annihilation through Higgs exchange or coannihilation Determination of parameters at colliders ?

• Precision required on masses expected to be similar to Higgs funnel scenario of MSSM

Cosmological scenario Different cosmological

scenario might affect the relic density of dark matter

Example: quintessence• Quintessence contribution

forces universe into faster expansion

• Annihilation rate drops below expansion rate at higher temperature

• Increase relic density of WIMPS

• In MSSM: can lead to large enhancements Profumo, Ullio, hep-ph/0309220

Baryon asymmetry of universe Small excess of particles over

antiparticles in the universe Both Big Bang Nucleosynthesis (BBN)

and measurements of CMB agree

Conditions to create an excess• Baryon number violation

• C and CP violation

• Out of thermal equilibrium

• Non-vanishing B-L Need physics Beyond the SM

Electroweak baryogenesis Baryon number generation at electroweak phase transition Need strong first order phase transition Finite temperature effective potential

• V= AT2φ2 - ET φ3+ λφ4 , condition : 2E/λ>1

• In SM requires Higgs mass < 50 GeV New physics solution:

• Bosonic loops: light stops in MSSM (Carena et al..)

• New strongly coupled fermions

• Modification of tree-level potential• NMSSM, SUSY with U(1)’ (Kang et al, 2005)

• Higher-order operators in Higgs-potential • Kanemura, Okada, Senaha (2004) , Grojean, Servant, Wells (2004)

EW baryogenesis and ILC

Whether electroweak baryogenesis is realised with new particles or modification of the Higgs sector, there will be signals at colliders (and edm)

Light RH stop in MSSM + light neutralino/ chargino +CP • Light RH stop for 1st order phase transition• New CP phases from and A• Discovery potential at Tevatron/LHC/ILC + edm• Signals for CP violation at ILC

• Prediction for relic density of DM in this model

Scenario with light stop

Can explain both dark matter and baryon asymmetry

ILC extend discovery range of Tevatron • Freitas et al, Snowmass

Improvement of edm limit -> strong constraint on model • Balazs et al 2005

CP violation and ILC

CP even observables can be used to determine phases in MSSM, unambiguous signal from CP- and T-odd asymetries at ILC

Many studies with neutralino/ chargino production and decays• T-odd triple product

• CP odd asymmetries with transverse beam polarization

S. Hesselbach, Snowmass

Relic density and phases

Strong dependence on phases even after taking into account shifts in masses

For example, in stop coannihilation scenario ~ factor 2

Need to measure precisely spectrum and couplings of LSP (including phases) GB et al, hep-ph/0604150

Conclusions and remarks In most scenarios, LHC will not provide sufficient precise information

to probe cosmology large uncertainties from particle physics models remain.

ILC fare much better especially without underlying theoretical assumption

More detailed studies needed both in MSSM and for other dark matter candidates

Note that it might also be possible with collider data to show that expected relic density is below WMAP pointing towards different cosmological model or other dark matter candidate

• In this case correlation with signals from direct/indirect detection important (expect large signals for Higgsino LSP)

ILC can also test models of baryogenesis

Higgs self-coupling and EWBG

Electroweak baryogenesis requires a large correction to the finite temperature effective potential.

The zero temperature potential is also expected to receive a large correction.

In particular modification of triple Higgs boson coupling can be measured at ILC

For example in 2HDM and MSSM. S.Kanemura, Y. Okada, E.Senaha, 2004

Triple Higgs coupling at ILC

Requiring a strong enough first order phase transition for EWBG,

Yasui et al, GLC report

Other DM candidates: gravitino Gravitino LSP has extremely weak interactions SUPERWIMP->

irrelevant during thermal freeze-out NLSP freeze-out as usual (can be slepton, neutralino..) and Ω

can be ~0.1 NLSP eventually decay to SM+gravitino ΩG = mG/mNLSP ΩNLSP Relic density naturally of right order Consequences on BBN or on leptogenesis Wide range of masses 100GeV-TeV possible for slepton-NLSP No hope of detecting in direct/indirect detection Colliders:

• search for metastable NLSP (104-108 s)(trapped in water tanks at LHC/ILC )

• Feng, Smith, hep-ph0409278

MSSM: coannihilation

Coannihilation scenario at large tanβ is more challenging

Strong dependence of relic density on tanβ

Could be determined from measurement of ΓA

M0=213, M1/2=360 tanβ=40

Baltz et al

With WMAP cosmology has entered precision era, can quantify amount of dark matter. In 2007 PLANCK satellite will go one step further (expect to reach precision of 2-3%). This strongly constrain some of the proposed solutions for cold dark matter

Has triggered many direct/indirect searches for dark matter

At colliders one can search for the particle proposed as dark matter candidates

So far no evidence (LEP-Tevatron) but in 2007 with Large Hadron Collider (LHC) at CERN will really start to explore a large number of models and might find a good dark matter candidate

.094 < ΩCDMh2 <.129